ALBERT

Notizen: Cambrian orogenesis (550–490 Ma) in the Lambert Province of the southern Prince Charles Mountains resulted in three successive stages of deformation. The earliest of these deformations resulted in the development of a layer-parallel foliation (S1) that was folded into macro-scale recumbent folds (F2). Subsequent deformation buckled the rocks into long-wavelength (c. 20 km), SW- to NW-trending antiformal closures (F3) mostly separated from each other by west to SW trending, steeply dipping, high-strain zones. Metapelitic rocks from the region are divisible into two compositional types: a high-Al, -Fe and -K type and a high-Mg, -Ca and -Na type. In rocks of both composition, relic staurolite preceded the formation of upper amphibolite facies garnet + biotite + sillimanite ± muscovite mineral assemblages that record peak pressures and temperatures of c. 650–700 °C and 6–7 kbar. Subsequent decompression of c. 3 kbar is implied from texturally late plagioclase and a reduction in the modal abundance of garnet in the high-Al, -Fe and -K metapelites, and from texturally late cordierite in the more magnesium rocks. This clockwise P–T–t path, with prograde heating followed by rapid decompression, is: (i) equivalent to that recorded in the same-aged rocks at Prydz Bay located 600 km to the north, and (ii) similar to the modelled response of the crust to thickening following continent–continent collision. These results indicate that large areas of East Antarctica were thickened and rapidly exhumed, probably in response to collisional orogenesis during the Early Cambrian. This supports the inference that Early Cambrian orogenesis in the Prydz Bay–Prince Charles Mountains region of East Antarctica marks one of the fundamental lithospheric boundaries within Gondwana.

Notizen: Interlayered graphitic and non-graphitic schists from the Tauern Window, Eastern Alps, record contrasting mechanical behaviour during extensional exhumation. Graphitic schists contain mesoscale extension fractures, pervasive microcracks in garnet, and abundant secondary fluid inclusion planes; all three types of structures are oriented perpendicular to the stretching lineation. Crack spacings in garnet from graphitic samples are tightly clustered around a mean of 180 μm. Non-graphitic schists have fewer and more randomly oriented microcracks and fluid inclusion planes and maintained strain compatibility via crystal plasticity. The presence or absence of graphite appears to have exerted a fundamental control on rheology during unroofing. Calculations for a model graphitic rock at 500 °C and fO2 = 10−24 MPa show that the equilibrium metamorphic fluid evolves from XCO2 = 0.07 to 0.38 during decompression from 700 to 400 MPa, in agreement with microcrack fluid inclusion data that show a change from XCO2 〈 0.1 to 0.45 in graphitic samples over the same pressure interval. This compositional shift results in 〉60% expansion of the pore fluid during decompression. H2O-rich fluid in non-graphitic rocks expands 〈15% over the same pressure interval. The greater pore fluid expansion in low-permeability graphitic horizons likely promoted tensile failure during unroofing. These results suggest that microcracking should be an inevitable consequence of decompression in many graphitic schists, whereas rocks that lack graphite are less likely to undergo microcracking. Microseismicity is predicted to be more common in graphitic than non-graphitic rocks during unroofing of mountain belts.

Notizen: The 3D shape, size and orientation data for white mica grains sampled along two transects of increasing metamorphic grade in the Otago Schist, New Zealand, reveal that metamorphic foliation, as defined by mica shape-preferred orientation (SPO), developed rapidly at sub-greenschist facies conditions early in the deformation history. The onset of penetrative strain metamorphism is marked by the rapid elimination of poorly oriented large clastic mica in favour of numerous new smaller grains of contrasting composition, higher aspect ratios and a strong preferred orientation. The metamorphic mica is blade shaped with long axes defining the linear aspect of the foliation and intermediate axes a partial girdle about the lineation. Once initiated, foliation progressively intensified by an increase in the aspect ratio, size and alignment of grains, although highest grade samples within the chlorite zone record a decrease in aspect ratio and reduction in SPO strength despite continued increase in grain size. These trends are interpreted in terms of progressive competitive anisotropic growth of blade-shaped grains so that the fastest growth directions and blade lengths tend to parallel the extension direction during deformation. The competitive nature of mica growth is indicated by the progressive increase in size and resultant decrease in number of metamorphic mica with increasing grade, from c. 1000 relatively small mica grains per square millimetre of thin section at lower grades, to c. 100 relatively large grains per square millimetre in higher grade samples. Reversal of SPO intensity and grain aspect ratio trends in higher grade samples may reflect a reduction in the strain rate or reduction in the deviatoric component of the stress field.

Notizen: The assumption of oxygen isotope and major element equilibrium during prograde metamorphism was tested using staurolite-grade pelitic schists that have undergone sequential porphyroblast growth and multiple episodes of recrystallization of matrix minerals and foliation development. Textural relationships are used to infer a metamorphic history that involves garnet growth followed by staurolite growth, with each porphyroblast growth event followed by at least one period of recrystallization of matrix minerals. Conventional geothermobarometry using Qtz–Grt–Pl–Ms–Bt ± St equilibria yields peak P–T conditions of c. 625 °C at 9–11 kbar, consistent with KMnFMASH petrogenetic grid predictions for stability of the assemblage Grt + St + Bt. Qtz–Grt oxygen isotope fractionations yield apparent temperatures of c. 590 °C and Qtz–St fractionations yield an apparent temperature of c. 595 °C. Diffusional modelling indicates that quartz isotopic compositions were reset by c. 30 °C via retrograde isotopic diffusional exchange with micas. The isotopic temperatures appear to be in excellent agreement with one another, and suggest oxygen isotope equilibrium was attained between garnet and staurolite at c. 625 °C. However, the agreement of Qtz–Grt and Qtz–Str isotopic temperatures is not consistent with petrographic observations (garnet grew before staurolite) and petrogenetic grid constraints that predict that garnet grows over a temperature interval of c. 525–550 °C. Given that: (i) oxygen diffusion rates in staurolite and garnet are slow enough to render an individual porphyroblast effectively closed to exchange after it forms; and (ii) matrix minerals are able to exchange isotopes via recrystallization during each period of deformation; garnet and staurolite could not have simultaneously achieved oxygen isotope equilibrium with each other or with minerals in the recrystallized matrix. Thus, the Qtz–Grt fractionations, which yield apparent temperatures that are in apparent agreement with peak metamorphic temperature and apparent temperatures for Qtz–St fractionations, cannot be fractionations resulting from equilibrium isotopic exchange. Instead, they are apparent fractionations between porphyroblasts formed at different temperature and times in the prograde P–T–D path, and quartz that recrystallized and exchanged with micas and plagioclase during several phases of deformation.

Notizen: Shape, size and orientation measurements of quartz grains sampled along two transects that cross zones of increasing metamorphic grade in the Otago Schist, New Zealand, reveal the role of quartz in the progressive development of metamorphic foliation. Sedimentary compaction and diagenesis contributed little to the formation of a shape-preferred orientation (SPO) within the analysed samples. Metamorphic foliation was initiated at sub-greenschist facies conditions as part of a composite S1-bedding structure parallel to the axial planes of tight to isoclinal F1 folds. An important component of this foliation is a pronounced quartz SPO that formed dominantly by the effect of dissolution–precipitation creep on detrital grains in association with F1 strain. With increasing grade, the following trends are evident from the SPO data: (i) a progressive increase in the aspect ratio of grains in sections parallel to lineation, and the development of blade-shaped grains; (ii) the early development of a strong shape preferred orientation so that blade lengths define the linear aspect of the foliation (lineation) and the intermediate axes of the blades define a partial girdle about the lineation; (iii) a slight thinning and reduction in volume of grains in the one transect; and (iv) an actual increase in thickness and volume in the survivor grains of the second transect. The highest-grade samples, within the chlorite zone of the greenschist facies, record segregation into quartz- and mica-rich layers. This segregation resulted largely from F2 crenulation and marks a key change in the distribution, deformation and SPO of the quartz grains. The contribution of quartz SPO to defining the foliation lessens as the previously discrete and aligned detrital quartz grains are replaced by aggregates and layers of dynamically recrystallized quartz grains of reduced aspect ratio and reduced alignment. Pressure solution now affects the margins of quartz-rich layers rather than individual grains. In higher-grade samples, therefore, the rock structure is characterized increasingly by segregation layering parallel to a foliation defined predominantly by mica SPO.

Notizen: The Tres Arboles ductile fault zone in the Eastern Sierras Pampeanas, central Argentina, experienced multiple ductile deformation and faulting events that involved a variety of textural and reaction hardening and softening processes. Much of the fault zone is characterized by a (D2) ultramylonite, composed of fine-grained biotite + plagioclase, that lacks a well-defined preferred orientation. The D2 fabric consists of a strong network of intergrown and interlocking grains that show little textural evidence for dislocation or dissolution creep. These ultramylonites contain gneissic rock fragments and porphyroclasts of plagioclase, sillimanite and garnet inherited from the gneissic and migmatitic protolith (D1) of the hangingwall. The assemblage of garnet + sillimanite + biotite suggests that D1-related fabrics developed under upper amphibolite facies conditions, and the persistence of biotite + garnet + sillimanite + plagioclase suggests that the ultramylonite of D2 developed under middle amphibolite facies conditions. Greenschist facies, mylonitic shear bands (D3) locally overprint D2 ultramylonites. Fine-grained folia of muscovite + chlorite ± biotite truncate earlier biotite + plagioclase textures, and coarser-grained muscovite partially replaces relic sillimanite grains. Anorthite content of shear band (D3) plagioclase is c. An30, distinct from D1 and D2 plagioclase (c. An35). The anorthite content of D3 plagioclase is consistent with a pervasive grain boundary fluid that facilitated partial replacement of plagioclase by muscovite. Biotite is partially replaced by muscovite and/or chlorite, particularly in areas of inferred high strain. Quartz precipitated in porphyroclast pressure shadows and ribbons that help define the mylonitic fabric. All D3 reactions require the introduction of H+ and/or H2O, indicating an open system, and typically result in a volume decrease. Syntectonic D3 muscovite + quartz + chlorite preferentially grew in an orientation favourable for strain localization, which produced a strong textural softening. Strain localization occurred only where reactions progressed with the infiltration of aqueous fluids, on a scale of hundreds of micrometre. Local fracturing and microseismicity may have induced reactivation of the fault zone and the initial introduction of fluids. However, the predominant greenschist facies deformation (D3) along discrete shear bands was primarily a consequence of the localization of replacement reactions in a partially open system.

Notizen: Metapelites, migmatites and granites from the c. 2 Ga Mahalapye Complex have been studied for determining the P–T–fluid influence on mineral assemblages and local equilibrium compositions in the rocks from the extreme southwestern part of the Central Zone of the Limpopo high-grade terrane in Botswana. It was found that fluid infiltration played a leading role in the formation of the rocks. This conclusion is based on both well-developed textures inferred to record metasomatic reactions, such as Bt ⇒ And + Qtz + (K2O) and Bt ± Qtz ⇒ Sil + Kfs + Ms ± Pl, and zonation of Ms | Bt + Qtz | And + Qtz and Grt | Crd | Pl | Kfs + Qtz reflecting a perfect mobility (Korzhinskii terminology) of some chemical components. The conclusion is also supported by the results of a fluid inclusion study. CO2 and H2O (〈inlineGraphic alt="inline image" href="urn:x-wiley:02634929:JMG579:JMG_579_mu1" location="equation/JMG_579_mu1.gif"/〉 = 0.6) are the major components of the fluid. The fluid has been trapped synchronously along the retrograde P–T path. The P–T path was derived using mineral thermobarometry and a combination of mineral thermometry and fluid inclusion density data. The Mahalapye Complex experienced low-pressure granulite facies metamorphism with a retrograde evolution from 770 °C and 5.5 kbar to 560 °C and 2 kbar, presumably at c. 2 Ga.

Notizen: Quartzo-feldspathic veins emplaced within a migmatite terrane near Wilson Lake in the Grenville Province of central Labrador record a metamorphic event not evident in the host rocks. The discordant veins are undeformed and have undisturbed primary igneous/hydrothermal textures. Most of the veins contain euhedral kyanite, as well as aggregates of kyanite, K-feldspar, phlogopite and minor dumortierite which are likely pseudomorphs after primary phengite. The reconstructed phengite compositions range from 3.1 to 3.2 Si per 11 oxygen formula unit. The pseudomorph assemblage is interpreted as the product of phengite + quartz melting under H2O-undersaturated conditions, which brackets P–T conditions of formation to about 9–16 kbar and 775–875 °C. A parallel vein that is likely of the same generation contains the borosilicate phases, dumortierite, prismatine and grandidierite, but no kyanite. The borosilicate assemblages constrain the P–T conditions of vein crystallization to ≥10 kbar and c. 750–850 °C. Vein emplacement is constrained to T ≤ 875 °C at the same pressures, which is well within the kyanite zone.Because the host rocks and veins must have experienced the same P–T history following vein emplacement, the presence of unreacted sillimanite in the host migmatites implies insufficient time for host rock equilibration. Slow reaction rates because of anhydrous conditions are not a likely explanation given the abundance of biotite and hornblende in the host rocks. The ductility implied by the breakdown of a hydrous phase (phengite) and the production of an H2O-undersaturated melt in the veins contrasts with the apparently brittle behaviour of the host rocks. The absence of deformation since the time of vein emplacement, even at temperatures above 750 °C, suggests that the deep crust in this part of Labrador had a very short residence time under conditions of the kyanite zone. Rapid decompression from those conditions is consistent with quartz + phengite melting and accounts for the relatively brittle behaviour of the terrane as it was uplifted.

Notizen: Regionally metamorphosed metapelites from Rogaland, SW Norway, contain zircon formed during the decompression reaction garnet + sillimanite + quartz → cordierite. The zircon, which occurs as inclusions in cordierite coronas around garnet, is texturally, chemically and isotopically distinct from older zircon in other textural settings in the matrix. A SHRIMP U–Pb age of 955 ± 8 Ma based on analyses in thin section on the decompression zircon from the cordierite coronas, therefore dates a point on the retrograde path, estimated from garnet–cordierite equilibria to be 5.6 kbar, 710 °C. This population was under-represented in conventional SHRIMP analyses of individual zircon in a mono-mineralic grain mount and, in the absence of a textural context, its significance unknown. The dominant age identified from SHRIMP analyses of the grain mount, in combination with analyses from matrix zircon in thin section, was 1035 ± 9 Ma. Based on the lack of consistent textural relationships with any specific minerals in thin section, as well as rare earth element chemistry, the 1035-Ma population is interpreted to represent zircon growth during incipient migmatization of the rocks at 6–8 kbar and c. 700 °C. This is consistent with previous estimates for the age of regional M1 metamorphism during the Sveconorwegian Orogeny. The most important outcome of this study is the successful analysis of zircon grains in a specific, well-constrained reaction texture. Not only does this allow a precise point on the regional P–T path to be dated, but it also emphasizes the possibility of zircon formation during the retrograde component of a typical metamorphic cycle.

Notizen: The subduction and exhumation of accretionary prism metasedimentary rocks are accompanied by large-strain ductile deformations which may be recorded in microstructures. Porphyroblast microstructures have been a key to unravel the kinematics in such deformed belts. Shape-preferred orientation (SPO) of epidote and amphibole inclusions that define S-shaped trails in prograde cores of plagioclase porphyroblasts were analysed from the high-P/T Sambagawa metamorphic rocks. Inclusions are found to be elongate parallel to the [010] and [001] directions, respectively, and their long-axis orientations define an internal foliation Si (best-fit great circle) and lineation Li (maximum on the Si). S-shaped inclusion trails in the orthogonal sections do not exhibit the same geometries, but rather are grouped into two types, where the foliation intersection axes (FIAs) are nearly perpendicular and parallel to Li, respectively. These two types of S-shaped inclusion trails are seen in the sections inclined at low and high angles to the Li, respectively. However, the latter type commonly consists of composite trails, where the Si is first rotated about an FIA perpendicular to the Li (i.e. unique axis), and then about an FIA parallel to the Li. The S-shaped inclusion trails are interpreted to have formed by the successive overgrowth of matrix minerals and rotation of the plagioclase porphyroblast cores about a unique axis in non-coaxial deformation. The rotation of Si about an FIA nearly parallel to the Li is perhaps an apparent rotation, caused by the deflection of foliation around the growing prismatic plagioclase grain prior to inclusion into the porphyroblast. This study has for the first time documented the 3-D geometry of S-shaped inclusion trails in porphyroblasts from accretionary prism metasedimentary rocks and identified their origin, which helps to understand the flow kinematics in the deeper part of a subduction channel.

Notizen: In the Orlica-Śnieżnik complex at the NE margin of the Bohemian Massif, high-pressure granulites occur as isolated lenses within partially migmatized orthogneisses. Sm–Nd (different grain-size fractions of garnet, clinopyroxene and/or whole rock) and U–Pb [isotope dilution-thermal ionization mass spectrometry (ID-TIMS) single grain and sensitive high-resolution ion microprobe (SHRIMP)] ages for granulites, collected in the surroundings of Červený Důl (Czech Republic) and at Stary Gierałtów (Poland), constrain the temporal evolution of these rocks during the Variscan orogeny. Most of the new ages cluster at c. 350–340 Ma and are consistent with results previously reported for similar occurrences throughout the Bohemian Massif. This interval is generally interpreted to constrain the time of high-pressure metamorphism. A more complex evolution is recorded for a mafic granulite from Stary Gierałtów and concerns the unknown duration of metamorphism (single, short-lived metamorphic cycle or different episodes that are significantly separated in time?). The central grain parts of zircon from this sample yielded a large spread in apparent 206Pb/238U SHRIMP ages (c. 462–322 Ma) with a distinct cluster at c. 365 Ma. This spread is interpreted to be indicative for variable Pb-loss that affected magmatic protolith zircon during high-grade metamorphism. The initiating mechanism and the time of Pb-loss has yet to be resolved. A connection to high-pressure metamorphism at c. 350–340 Ma is a reasonable explanation, but this relationship is far from straightforward. An alternative interpretation suggests that resetting is related to a high-temperature event (not necessarily in the granulite facies and/or at high pressures) around 370–360 Ma, that has previously gone unnoticed. This study indicates that caution is warranted in interpreting U–Pb zircon data of HT rocks, because isotopic rejuvenation may lead to erroneous conclusions.

Notizen: The development of shear zones at mid-crustal levels in the Proterozoic Willyama Supergroup was synchronous with widespread fluid flow resulting in albitization and calcsilicate alteration. Monazite dating of shear zone fabrics reveal that they formed at 1582 ± 22 Ma, at the end of the Olarian D3 deformational event and immediately prior to the emplacement of regional S-type granites. Two stages of fluid flow are identified in the area: first an albitizing event which involved the addition of Na and loss of Si, K and Fe; and a second phase of calcsilicate alteration with additions of Ca, Fe, Mg and Si and removal of Na. Fluid fluxes calculated for albitization and calcsilicate alteration were 5.56 × 109 to 1.02 × 1010 mol m−2 and 2.57 × 108–5.20 × 109 mol m−2 respectively. These fluxes are consistent with estimates for fluid flow through mid-crustal shear zones in other terranes. The fluids associated with shearing and alteration are calculated to have δ18O and δD values ranging between +8 and +11‰, and −33 and −42‰, respectively, and ɛNd values between −2.24 and −8.11. Our results indicate that fluids were derived from metamorphic dehydration of the Willyama Supergroup metasediments. Fluid generation occurred during prograde metamorphism of deeper crustal rocks at or near peak pressure conditions. Shear zones acted as conduits for major crustal fluid flow to shallow levels where peak metamorphic conditions had been attained earlier leading to the apparent ‘retrograde’ fluid-flow event. Thus, the peak metamorphism conditions at upper and lower crustal levels were achieved at differing times, prior to regional granite formation, during the same orogenic cycle leading to the formation of retrograde mineral assemblages during shearing.

Notizen: The thermodynamic properties of silicate minerals can be described as a linear combination of the fractional properties of their constituent polyhedra. In contrast, given the thermodynamic properties of these polyhedra, the thermodynamic properties of minerals can be estimated, where only the crystallography of the mineral needs to be known. Such estimates are especially powerful for hypothetical mineral end-members or for minerals where experimental determination of their thermodynamic properties is difficult. In this contribution the fractional enthalpy, entropy and molar volume for 35 polyhedra have been determined using weighted multiple linear regression analysis on a data set of published mineral thermodynamic properties. The large number of polyhedra determined, allows calculation of a much larger variety of phases than was previously possible and the larger set of minerals used provides more confident fractional properties. The OH-bearing minerals have been described by partial and total hydroxide coordinated components, which gives better results than previous models and precludes the need of a S–V term to improve estimates of entropy. However, the fractional thermodynamic properties only give adequate results for silicate minerals and double oxides, and should therefore not be used to estimate the properties of other minerals. The thermodynamic properties of ‘new’ minerals are calculated from a linear stoichiometric combination of their constituent polyhedra, resulting in estimates generally with associated uncertainty of 〈5%. The quality of such data appears to be of sufficient accuracy for thermodynamic modelling as shown for meta-bauxites from the Alps and the Aegean, where the effect of Zn on the P–T stability of staurolite can be both qualitatively and quantitatively reproduced.

Notizen: Reaction progress exhibited by multivariant assemblages in micaceous limestones can provide an excellent record of metamorphic fluid flow. However, it is necessary to understand the sensitivity of these assemblages to bulk-composition parameters. Here, analysis of bulk composition on different scales and pseudosection construction are used to draw conclusions on relationships between bulk composition, fluid flow and reaction progress. Issues addressed include the effects of bulk composition on the mineralogical evolution of micaceous carbonates, the sensitivity of bulk composition to bulk-composition sampling methods, the magnitude of cross-layer fluid-composition gradients, the potential for metasomatism to drive reaction progress, and the relative timing of reaction in adjacent layers. Pseudosections successfully represent observed mineral assemblages, constrain the position of reactions in T–X(CO2) space, and allow assessment of the sensitivity of reaction position, inferred reaction progress and calculated fluid fluxes to uncertainties in bulk composition. The scale of bulk-composition sampling affects bulk compositions, calculated modes, predicted mineral assemblages and calculated fluid compositions. Larger samples record an average of different lithological subdomains, while point-count-derived bulk compositions are subject to uncertainties related to the small number of sample points. The optimum bulk composition for pseudosection purposes probably lies between measured bulk compositions. Results suggest that reaction progress in some extensively reacted layers was driven by infiltration of H2O-rich fluid which flowed or diffused parallel to layering, perpendicular to layering in response to fluid-composition gradients, and out of veins. Small variations in fluid composition across layering (ΔX(CO2) 〈 0.02) were maintained by internal buffering by the mineral assemblages. Internal buffering must also have driven samples up a sequence of narrow low-variance fields in T–X(CO2) space, and so reaction in adjacent layers must have close to simultaneous. Metasomatic effects on reaction progress are likely to have been small, so long as the porosity was low.

Notizen: Metapelitic residual enclaves in the Neogene Volcanic Province of SE Spain are residues left after melt extraction. Glass (quenched melt) of granitic composition occurs as inclusions in most minerals and as intergranular pockets. The most common enclave types show one stage of garnet growth that is interpreted to have occurred at the same time as glass production. Some of these show a well-developed foliation outlined by fibrolite, biotite, graphite and glass, which wraps around elongate garnet crystals that have aspect ratios up to 10:1. Based on microstructures and chemistry, the garnet within these rocks shows clear core and mantle structure. The core has an average composition of Alm76–Prp08–Sps14–Grs03 and contains primary inclusions of biotite and melt, trapped during garnet growth. A thin (c. 100 μm), irregular mantle overgrows the garnet core, enclosing oriented fibrolite inclusions in strain caps, and biotite in strain shadows. In places, the overgrowths form skeletal elongated arms, which extend parallel to the foliation. The garnet mantle contains less Mn and higher XMg, but both core and mantle display flat Mn profiles, the contact being a sharp break. Ternary feldspar and Grt–Bt thermometry yield temperatures in the range 800–900 °C, with no systematic differences among the different microstructural domains of elliptical garnet. Based on the observed intracrystalline microstructures, the high amount of melt extraction in the rock by flattening component strain and the chemical zoning of garnet, the formation of elliptical garnet is modelled by a multistage sequence. This involves pressure solution and reprecipitation of the core, followed by post-kinematic, partly mimetic growth of the garnet mantle.

Notizen: High erosion potential of dewatered kimberlite mine tailings after diamond extraction has prompted research at the Ekati Diamond Mine in the Canadian subarctic heath tundra ecosystem. Coarse texture, no organic component, lack of available macronutrients, and a serpentine chemistry are the principal limitations of these kimberlite tailings to plant colonization. Structure-improving (peat moss, lake sediment, sewage sludge, Agri-Boost, and composted papermill sludge) and nutrient-providing (fertilizer, calcium carbonate, gypsum, and rock phosphate) amendments were tested in the greenhouse to ameliorate these limitations, thereby facilitating the field establishment of a permanent vegetation cover, which would stabilize the surface materials and promote natural colonization by the surrounding tundra vegetation. Seven native grass species (Arctagrostis latifolia, Calamagrostis canadensis, Poa glauca, Poa alpina, Deschampsia beringensis, Deschampsia caespitosa, and Festuca rubra) were used to measure amendment success. With the addition of structure-improving and nutrient-providing amendments, plant growth on kimberlite tailings was significantly enhanced. Tailings properties, including cation exchange capacity, percentage of organic carbon, and macronutrient availability, were also improved by amendment addition.

Notizen: Mechanical, biological, and chemical attempts to control invasive plants can be expensive, ecologically damaging, and frequently unsuccessful. This study proposes using the intrinsic biological attributes of the threatened plant community by artificially increasing the density of competitive native species to selectively suppress the growth of the invasive. Evidence from agricultural weed control suggests that oversowing infested areas with species with biological traits similar to those of the invasive species not only reduces productivity of the invasive species but also may eliminate environmental damage associated with standard control techniques. Annual bastard cabbage (Rapistrum rugosum), a Eurasian exotic, is an invader of native plant communities in the continental United States. Control with herbicides has been problematic due to high mortality of adjacent native species and subsequent perpetuation of a disturbed state that facilitates further regeneration of R. rugosum from the seed bank. In a randomized field experiment, sowing native Indian blanket (Gaillardia pulchella) over established seedling colonies of R. rugosum resulted in significant reduction of R. rugosum productivity (F= 3.43; p 〈 0.05). The highest sowing rate of G. pulchella resulted in a 72% reduction in aboveground productivity of R. rugosum that translated to an estimated 83% decrease in seed set, without significant suppression of adjacent native species. It is proposed that enriching threatened or infested plant communities with selected native species with matching phenologies and competitive characteristics has advantages over conventional control methods in that (1) it reduces the threat to nontarget organisms; (2) once installed, the species could self-regenerate; and (3) it does not perpetuate a disturbed (early-successional) state that might aggravate the problem. This may serve as an alternative technique to protect and restore native plant communities.

Notizen: Land application of municipal biosolids on coal mine spoils can benefit vegetation establishment in mine reclamation. However, the application of biosolids leads to domination by early-successional species, such as grasses, and low establishment of woody and volunteer species, thus reducing potential for forestry as a postmining land use. In this experiment, tree seedlings were planted in strips (0.6-, 1-, and 4-m wide) that were not seeded with grasses, and the effects of unseeded strip width on seedling growth and species richness were assessed. Planted seedling mortality was high; therefore, the effect of unseeded strip width on seedling growth could not be determined. However, it was found that natural plant invasion and species richness were highest in the 4-m unseeded strips. The practice of leaving 4-m-wide unseeded strips in mine reclamation with biosolids in the eastern United States, along with the improvement of tree seedling planting practices and planting stock, would help promote a more species-rich plant community that could be utilized for forestry or a variety of other postmining land uses.

Notizen: Grassy woodlands dominated by Eucalyptus species such as E. albens Benth., E. melliodora A. Cunn. ex Schauer, and E. microcarpa Maiden are poorly conserved in Australia, owing to widespread agricultural development. Understorey restoration is vitally important to enhance degraded remnants but no reliable techniques are available to restore herbaceous understorey species over large areas. Reestablishment of dominant native grasses such as Kangaroo grass (Themeda triandra Forssk.) is particularly important. This study compared Themeda establishment using a variety of sowing techniques across a range of landscape positions in degraded woodlands in central New South Wales. Four localities were sampled at three landscape positions (upper, mid-, and lower slopes). Existing vegetative cover was sprayed with herbicide and removed by mowing. A randomized block experiment was established at each site with five replicates of five seedbed treatments: all four factorial combinations of soil disturbance (disturbed, nondisturbed) and weed control (atrazine, nonatrazine), plus topsoil scalping followed by soil disturbance. After 117 days, all plots were subject to a common herbicide (atrazine) treatment to control weeds. Themeda establishment was not significantly affected by landscape position, despite significant differences in the cover of exotic species among landscape positions. The scalped/disturbed treatment resulted in significantly better establishment at 400 days (18% or 3.9 plants/m2) than the control (8% or 1.8 plants/m2). All other treatments did not differ significantly from the control suggesting that seedbed treatments are not critical to successful Themeda establishment. These results suggest that Themeda swards can be reestablished in degraded woodlands relatively simply. The similarity in outcomes across all landscape positions suggests that general recommendations for “best-bet” establishment methods may prove robust under a wide range of environmental and seasonal conditions.

Notizen: The criteria of restoration success should be clearly established to evaluate restoration projects. Recently, the Society of Ecological Restoration International (SER) has produced a Primer that includes ecosystem attributes that should be considered when evaluating restoration success. To determine how restoration success has been evaluated in restoration projects, we reviewed articles published in Restoration Ecology (Vols. 1[1]–11[4]). Specifically, we addressed the following questions: (1) what measures of ecosystem attributes are assessed and (2) how are these measures used to determine restoration success. No study has measured all the SER Primer attributes, but most studies did include at least one measure in each of three general categories of the ecosystem attributes: diversity, vegetation structure, and ecological processes. Most of the reviewed studies are using multiple measures to evaluate restoration success, but we would encourage future projects to include: (1) at least two variables within each of the three ecosystem attributes that clearly related to ecosystem functioning and (2) at least two reference sites to capture the variation that exist in ecosystems.

Notizen: The restoration potential of Sweetgrass (Anthoxanthum nitens (Weber) Y. Schouten & Veldkamp) was evaluated through a field experiment conducted on Kanatsiohareke, a Mohawk farm, and at the LaFayette Experiment Station near Syracuse, New York. The effects of competition reduction and two cover crops on Sweetgrass reestablishment success were examined. Sweetgrass was planted under four treatments: Sweetgrass alone; with existing, old-field vegetation; with a cover crop of Hairy vetch (Vicia villosa); and with a cover crop of Annual (Italian) ryegrass (Lolium multiflorum). The experiment consisted of five replicates of the four treatments at both LaFayette and Kanatsiohareke. Sweetgrass biomass, height, reproduction rate, and survivorship were greatest in plots that were weeded to eliminate competition and in plots with Hairy vetch as a cover crop. A cover crop of Annual ryegrass resulted in reduced Sweetgrass growth and reproduction. The results of this field experiment indicate that there is great restoration potential for Sweetgrass because it is easily transplanted and reproduces vigorously. For 2.25-m2 plots, Hairy vetch is an effective cover crop for Sweetgrass. Planting the Sweetgrass with Hairy vetch generated properties of the grass that are desired by basketmakers, such as abundance and tall blades. This technique also allowed for a relatively non–labor intensive method of cultivation. Reestablishment of Sweetgrass offers the members and visitors of Kanatsiohareke the means to continue to use the plant, strengthen traditional practices associated with Sweetgrass, and benefit economically by selling baskets and medicine made with Sweetgrass.

Notizen: Whether restoration programs successfully reinstate ecological interactions remains a contentious and largely untested issue. We investigated plant and pollinator interactions on two old and two restored hay meadows, with the aim of evaluating if quantitative patterns of insect visitation and pollen transport were comparable among old and restored meadows. In terms of structural diversity, few species of plants and insects were shared among the webs. In all four meadows, Diptera and Hymenoptera dominated the visitor community in terms of both species richness and abundance. Coleoptera, Hemiptera, and Lepidoptera comprised the remainder of the flower visitors. No significant difference was found between restored and old sites in plant or insect species richness or in plant and insect abundance. In terms of function, the meadows appeared more similar, although a slightly higher proportion of the potential links between plants and insects was realized for old meadows. No difference was found in the proportion of plant species visited, and visited plant species were generalized, with all having more than a single species of insect visitor. We also sampled approximately 400,000 pollen grains from the flower-visiting insects. There were no differences between old and restored sites in the amount of pollen being transported or in the average number of pollen grains per insect. At both types of meadows, Hymenoptera carried most pollen, followed by Diptera. Again, generalization was the norm, with all plants having more than a single species of pollen carrier. No difference was observed in the connectance of pollen transport webs between old and restored sites. Overall, although the four meadows showed considerable structural variation, they showed similarity with regard to the functional processes we studied. Because structural variation is expected among localities, we conclude that the two restoration projects have been successful.

Notizen: Current restoration measures of degraded, acidified heathland ecosystems have not always been successful in the Netherlands. Positive effects of a restored hydrology are often counteracted by acidification of the soil and the local groundwater system. Liming of the heathlands in the catchment of moorland pools might contribute to the restoration of both habitats. Experimental catchment liming was carried out in two degraded Dutch heathlands, with doses varying between 2 and 6 tons/ha. Catchment liming resulted in increased pH and base cation concentrations in the highest elevated limed parts, as well as in the lower situated, nonlimed heath areas and moorland pools. Generally, catchment liming created suitable conditions for the return of heathland target species, and the positive effects lasted for at least 6 years. The response of the heathland vegetation to the liming has, however, been slow because only a small number of endangered plant species increased in abundance. In contrast, four Red List soft-water macrophytes strongly increased in abundance in the moorland pool. Our results show that, even with the slow return of Red List plant species, catchment liming can be a successful management tool for the restoration of the acidified heathland landscape.

Notizen: Phalaris arundinacea L. is an aggressive species that can dominate wetlands by producing monotypic stands that suppress native vegetation. In this study invasion windows were created for native species in monotypic stands of P. arundinacea with either fire or herbicide. Three native species groups, herbaceous plants, herbaceous seeds, and woody shrubs, were planted into plots burned or treated with herbicide in the early spring. Fire did not create an effective invasion window for native species; there was no difference in P. arundinacea root and shoot biomass or cover between burned and control plots (p≥ 0.998). Herbicide treatment created an invasion window for native species by reducing P. arundinacea root and shoot biomass for two growing seasons, but that invasion window was fast closing by the end of the second growing season because P. arundinacea shoot biomass had nearly reached the shoot biomass levels in the control plots (p= 0.053). Transplant mortality, frost, and animal herbivory prevented the herbaceous species and woody seedlings from becoming fully established in the plots treated with herbicide during the first year of the experiment. Transplanted monocots had a greater survival than dicots. By the second growing season the herbaceous group had the greatest mean areal cover (5%), compared to the woody seedlings (3%) and seed group (0%). Long-term monitoring of the plots will determine whether the herbaceous transplants will compete effectively with P. arundinacea and whether the woody species will survive, shade the P. arundinacea, and accelerate forest succession.

Notizen: Invasive plants are one of the most serious threats to native species assemblages and have been responsible for the degradation of natural habitats worldwide. As a result, removal of invasive species and reestablishment of natural vegetation have been attempted in order to restore biodiversity and ecosystem function. This study examined how native arthropod assemblages, an abundant and functionally important group of organisms in many ecosystems, are affected by the incursion of the invasive wetland plant Phragmites australis and if the restoration of the native vegetation in brackish Spartina alterniflora marshes results in the reestablishment of the arthropod community. The invasion of Phragmites into a coastal Spartina marsh in southern New Jersey seriously altered arthropod assemblages and trophic structure by changing the abundance of trophic groups (detritivores, herbivores, carnivores) and their taxonomic composition. Herbivore assemblages shifted from the dominance of external free-living specialists (e.g., planthoppers) in Spartina to concealed feeders in Phragmites (stem-feeding cecidomyiids). Moreover, free-living arthropods in Phragmites became dominated by detritivores such as Collembola and chironomids. The dominant marsh spiders, web-building linyphiids, were significantly reduced in Phragmites habitats, likely caused by differences in the physical environment of the invaded habitats (e.g., lower stem densities). Thus, trophic structure of arthropod assemblages in Phragmites, as seen in the large shifts in feeding guilds, was significantly different from that in Spartina. Removal of Phragmites with the herbicide glyphosate resulted in the rapid return of Spartina (≤5 yrs). Moreover, return of the dominant vegetation was accompanied by the recovery of most original habitat characteristics (e.g., live and dead plant biomass, water flow rate). The arthropod assemblage associated with Spartina also quickly returned to its preinvasion state and was not distinguishable from that in uninvaded Spartina reference sites. This study provides evidence that the reestablishment of native vegetation in areas previously altered by an invasive plant can result in the rapid recovery of the native arthropod assemblage associated with the restored habitat.

Notizen: Habitat restoration resulting in changes in plant community composition or species dominance can affect the spatial pattern and variability of soil nutrients. Questions about how these changes in soil spatial heterogeneity develop over time at restoration sites, however, remain unaddressed. In this study, a geostatistical approach was used to quantify changes over time in the spatial heterogeneity of soil organic matter (SOM) across a 26-year chronosequence of tallgrass prairie restoration sites at FermiLab, outside of Chicago, Illinois. We used total soil N and C as an index of the quantity of SOM. We also examined changes in C:N ratio, which can influence the turnover of SOM. Specifically, the spatial structure of total N, total C, and C:N ratio in the top 10 cm of soil was quantified at a macroscale (minimum spacing of 1.5 m) and a microscale (minimum spacing of 0.2 m). The magnitude of spatial heterogeneity (MSH) was characterized as the proportion of total sample variation explained by spatially structured variation. At the macroscale, the MSH for total N decreased with time since restoration (r2= 0.99, p 〈 0.001). The decrease in spatial heterogeneity over time corresponded with a significant increase in the dominance of the C4 grasses. At the microscale, there was significant spatial structure for total N at the 4-year-old, 16-year-old, and 26-year-old sites, and significant spatial structure for total C at the 16-year-old and 26-year-old sites. These results suggest that an increase in dominance of C4 grasses across the chronosequence is homogenizing organic matter variability at the field scale while creating fine-scale patterns associated with the spacing of vegetation. Areas of higher soil moisture were associated with higher soil N and C at the two oldest restoration sites and at the native prairie site, potentially suggesting patches of increased belowground productivity in areas of higher soil moisture. This study is one of the first to report significant changes over time in the spatial structure of organic matter in response to successional changes initiated by restoration.

Notizen: The occurrence of lawsonite is described from pelitic schists of the lower-grade part of the pumpellyite-bearing subzone of the chlorite zone in the Asemi River area of central Shikoku. The lawsonite-bearing parageneses are consistent with the generally accepted view that the Sanbagawa facies series represents higher pressures than the lawsonite-bearing facies series in New Zealand.

Notizen: Abstract Late Archaean orthogneisses and aluminous and iron-rich metasedimentary rocks intruded by anorthosite and a ferrodiorite-granite suite were completely recrystallized during Proterozoic granulite facies metamorphism. Geobarometry and geothermometry indicate P-T conditions of around 7.5kbar. 700°C, with a CO2-rich fluid phase and logfO2 at or below -16. A two-stage high-grade history of near isochemical corona growth is preserved in metasediments with the reaction cycle opx + plag + H2O → hbl+gar+SiO2→ opx+plag+H2O. End product compositions resemble those of the initial phases, and the only mobile components were SiO2 and/or H2O. The coronas reflect shortlived fluctuations in chemical activity at essentially constant P and T, contrary to simple progressive change in equilibrium parameters recorded by most corona-bearing textures.

Notizen: In a polymetamorphic, felsic, biotite-bearing gneiss, biotite has reacted to form magnetite and microcline. The resulting structure is a magnetite core surrounded by a mantle of feldspar and quartz normally not exceeding 20mm in diameter. Measurements of oxygen isotope ratios disclose disequilibrium between mantle microcline and mantle quartz and also between mantle and matrix minerals of the same species. A clustering of temperature estimates from the oxygen isotope distribution between magnetite and quartz and between magnetite and microcline in the interval 550 to 600°C suggests an approach to oxygen isotope equilibrium. No signs of a re-equilibriation of the reacting biotite can be found.

Notizen: Abstract Clinopyroxenes and garnets from 11 blueschist-facies Fe-rich eclogite samples from the Voltri Group show a wide range of chemical compositions. Detailed analyses of single pyroxene and garnet grains show wide and scattered chemical inhomogeneity, the KD(KD= (Fe2+/Mg)Gt/(Fe2+/Mg)Cpx) ranges from 20 to 87 based on rim analyses only. The data obtained indicate that the mineral pairs never attained equilibrium under uniform P-T conditions and that the compositions of the metamorphic minerals were influenced mainly by the composition of the pre-metamorphic minerals and by topotactical reactions.

Notizen: Abstract At Sulitjelma, Norway, there is a major inversion of metamorphic isograds beneath an inverted but undisrupted ophiolite. The flysch-like Furulund schist in which the inverted isograds occur is also inverted and the early folds in it are downward facing. The isograds cut across the axial surfaces of early folds and across the schistosity. These relationships are explained as the consequence of metamorphism during the progressive development of a large overfold. The inverted limb of the overfold is regarded as a major, thick, gently-dipping shear zone, separating the lower-grade, lower part of the Caledonian allochthon below from the higher-grade upper part of the allochthon above. The association between stratigraphical inversion, downward-facing of syn-schistosity folds and metamorphic inversion is explained by the progressive development of the shear zone. It is suggested that the presence of such shear zones is a common feature of orogenic belts formed by continental collision.

Notizen: Abstract The Hercynian granitic basement which forms the Tenda Massif in NE Corsica represents part of the leading edge of the European Plate during middle-to-late Cretaceous (Eoalpine) high P metamorphism. The metamorphism of this basement, induced by the overthrusting of a blueschist facies (schistes lustrés) nappe, was confined to a major ductile shear zone (c. 1000m thick) within which deformation increases upwards towards the overlying nappe. Metamorphism within the basement mostly records lower blueschist facies conditions (crossite + epidote) except near the base of the shear zone where the greenschist facies assemblage albite + actinolitic amphibole has developed instead of crossite. Study of the primary mafic phase breakdown reactions within hornblende granodiorite reveals the following metamorphic zonation. Zone 1: biotite to chlorite. Towards zone 2: biotite to phengite. Zone 2: Hornblende to actinolitic Ca-amphibole + albite + sphene, and biotite to actinolitic Ca-amphibole + albite + phengite + Ti-ore + epidote. Zone 3: Hornblende to crossite + low Ti-biotite + phengite + sphene, and biotite to crossite + low Ti-biotite + phengite + Ti-ore + sphene ± epidote. P-T conditions at the base of the shear zone are estimated to have been 390-490°C at 600-900 M Pa (6-9kbar) and the Corsican basement is therefore deduced to have been buried to 20-30 km during metamorphism. This relatively shallow metamorphism contrasts with some other areas in the Western Alps where the Eoalpine event apparently buried the European continental crust to depths of 80 km or more. As there is no evidence for a long history of blueschist facies metamorphism prior to the involvement of the European continent, it is deduced that the Eoalpine blueschists were produced during the collision of the Insubric plate with Europe, rather than during Tethyan intraoceanic subduction. Coherent blueschist terrains such as the schistes lustres probably record buovant feature collision and obduction tectonics rather than any preceding oceanic subduction.

Notizen: Abstract Three major blastomylonitic synmetamorphic (epidote amphibolite to mid amphibolite facies) shear zones are seen on the NW coast of the Mullet Peninsula in NW Mayo. These shear zones occur at the contacts of major structural units and in an imbricated slice where rocks of the Erris Complex are deformed and chemically modified. Chemical changes associated with individual shear zones have been deduced by comparing the compositions of various gneisses both within and adjacent to the shear zones. Compositional changes are different in the constituent rock-types within each unit and many elements normally considered immobile have been selectively mobilized within the shear zones. Little evidence of wholesale metasomatic introduction of components into these shear zones was found to accompany the selective mobilization.

Notizen: Abstract. In the Kamuikotan zone, central Hokkaido, Japan, two distinct types of metamorphic rocks are tectonically mixed up, along with a great quantity of ultramafic rocks; one type consists of high-pressure metamorphic rocks, and the other of low-pressure ones. The high-pressure metamorphic rocks are divided into two categories. (1) Prograde greenschist to glaucophaneschist facies rocks derived from mudstone, sandstone, limestone, a variety of basic rocks such as pillow and massive lavas, hyaloclastite and tuff, and radiolarian (Valanginian to Hauterivian) chert, among which the basic rocks and the chert, and occasionally the sandstone, occur as incoherent blocks (or inclusions) enveloped by mudstone. (2) Retrograde amphibolites with minor metachert and glaucophane-calcite rock, which are tectonic (or exotic) blocks enclosed within prograde mudstone or serpentinite, or separated from these prograde rocks by faults. The K-Ar ages of the prograde metamorphic rocks (72, 107 and 116 Ma on phengitic muscovites) are younger than those of the retrograde rocks (109, 132, 135 and 145 Ma on muscovites, and 120 Ma on hornblende). The low-pressure metamorphic rocks consist of the mafic members of an ophiolite sequence with a capping of radiolarian (Tithonian) chert with the metamorphic grade ranging from the zeolite facies, through the greenschist (partly, actinolite-calcic plagioclase) facies to the amphibolite (partly, hornblende-granulite) facies. The low-pressure metamorphism has a number of similarities with that described for‘ocean-floor’metamorphism. The tectonic evolution of such a mixed-up zone is discussed in relation to Mesozoic plate motion.

Notizen: The rocks of the Scourian Complex have been intensively studied, but there is still no consensus as to the conditions of the granulite-facies metamorphism preserved in these rocks. Recent estimates of these conditions fall into two groups, one at 820-920°C and ca. 11 kbar and the second at ca. 1000°C and 〉12 kbar. Investigation of a variety of rocks shows that the recorded conditions vary with grain-size, with higher-grade conditions recorded by the cores of coarser (ca. 10 mm) crystals, and lower-grade conditions recorded by the rims of coarser grains and by finer grains. This observation suggests that re-equilibration during recovery of these rocks to the surface has been important which may account for the discrepancy in estimated P-T conditions. Revised estimates of the equilibration conditions of the Scourian Complex of T 〉 1000°C and P 〉 8.5 kbar are presented. The conditions suggested for the peak of metamorphism mean that the role of anatexis in the genesis of these rocks must be considered and the nature of the fluid phase thoroughly investigated.

Notizen: Thermal models for Barrovian metamorphism driven by doubling the thickness of the radiogenic crust typically meet difficulty in accounting for the observed peak metamorphic temperature conditions. This difficulty suggests that there is an additional component in the thermal budget of many collisional orogens. Theoretical and geological considerations suggest that viscous heating is a cumulative process that may explain the heat deficit in collision orogens. The results of 2D numerical modelling of continental collision involving subduction of the lithospheric mantle demonstrate that geologically plausible stresses and strain rates may result in orogen-scale viscous heat production of 0.1 to 〉1 μW m−3, which is comparable to or even exceeds bulk radiogenic heat production within the crust. Thermally induced buoyancy is responsible for crustal upwelling in large domes with metamorphic temperatures up to 200 °C higher than regional background temperatures. Heat is mostly generated within the uppermost mantle, because of large stresses in the highly viscous rocks deforming there. This thermal energy may be transferred to the overlying crust either in the form of enhanced heat flow, or through magmatism that brings heat into the crust advectively. The amplitude of orogenic heating varies with time, with both the amplitude and time-span depending strongly on the coupling between heat production, viscosity and collision strain rate. It is argued that geologically relevant figures are applicable to metamorphic domes such as the Lepontine Dome in the Central Alps. We conclude that deformation-generated viscous dissipation is an important heat source during collisional orogeny and that high metamorphic temperatures as in Barrovian type metamorphism are inherent to deforming crustal regions.

Notizen: Metanorites from two eclogitized metagabbros of the Hercynian French Massif Central preserve coronitic textures of hornblende, garnet, quartz and/or kyanite produced at the expense of the primary magmatic assemblage orthopyroxene and plagioclase. Using a petrogenetic grid in the CFMASH system, two possible P–T evolutions for the origin of the coronas are evaluated. The sequence of reactions involving the formation of Hbl (–Ky) ± Grt and Qtz coronitic assemblages is consistent with an isobaric cooling at high pressure (c. 1–2 GPa) under hydrated conditions. However, this P–T path, inferred by using only petrographical observations, is inconsistent with the geochronological constraints: emplacement of the gabbro at 490 Ma and high-pressure metamorphism at 410 Ma. In order to reconcile petrographical observations with geochronological constraints, we propose a discontinuous two-stage evolution involving a change in water activity with time. (1) Emplacement and cooling of the norite at low pressure under anhydrous conditions, at 490 Ma. (2) During the Hercynian orogeny, the norite experienced an increase in pressure and temperature under fluid-present conditions. Adding water to the system implies a dramatic change in the petrogenetic grid topology, restricting the orthopyroxene–plagioclase assemblage only to high temperatures. Therefore, the breakdown of the unstable magmatic assemblage, through apparent retrograde reactions, occurred along the prograde P–T path which never crossed the equilibrium boundaries of these reactions.

Notizen: Detailed petrographic analysis was performed on samples from five localities within the southern Adirondacks. Textures and zoning patterns in garnet from all samples provide evidence for dehydration melting of biotite. Zoning of grossular in garnet – providing a record of prograde growth – shows both increasing and decreasing trends in garnet from the same sample. However, Ca concentrations at the garnet rims of most samples are identical (grossular = 3.4%). These observations have been interpreted as evidence for the differential timing of garnet nucleation and growth. All Fe/(Fe + Mg) and some spessartine distributions are consistent between samples, displaying diffusive profiles established largely upon cooling. Only one sample, in which retrogression was minimal, contains garnet with flat Fe/(Fe + Mg) profiles. A general pelitic pseudosection constructed in the system MnNCKFMASH reveals a maximum for Ca in garnet where the plagioclase-out isopleth intersects the solidus (muscovite = 0). The pseudosection predicts bell-shaped core-to-rim profiles of grossular during anatexis, similar to those observed in the rocks. Garnet–biotite thermometry and GASP barometry indicate peak temperatures of at least 790 °C at about 7–9 kbar, similar to conditions determined for the central Adirondacks. Cooling rates determined from finite difference modelling of spessartine and Fe/(Fe + Mg) diffusional profiles indicate a multi-stage cooling history in which some period of rapid cooling (〉200 °C Myr−1) is required.

Notizen: Abstract. Plagioclase porphyroblasts from silvergrey schists belonging to the Nevado Filabride Complex in the Sierra Alhamilla (Betic Zone, SE Spain) are interpreted as having been formed preand synkinematically with respect to the second phase of deformation. Different types of inclusion patterns represent 'snap-shots’(high growth-rate/strain-rate ratio features) of the formation of a diffentiated crenulation cleavage during this second phase of deformation, by the processes of kinking, crenulation and associated differentiation.Regional considerations indicate an Alpine age for this tectono-metamorphic event, which can be explained by the‘hot emplacement’of the higher Nevado Filabride units. The observed structural evolution is not consistent with a pre-Alpine polyphase deformation history.

Notizen: Evidence from rock microstructures, mass transfer and isotopic exchange indicates that substantial quantities of aqueous fluids are involved in low- and medium-grade regional metamorphism. Similar conclusions are drawn from many retrograde environments, whereas high-grade metamorphic fluids may be melt dominated. The mobile fluids play essential roles in metamorphic reactions, mass transport and deformation processes. These processes are linked by the mechanical consequences of metamorphic fluid pressures (Pf) generally being greater than or equal to the minimum principal compressive stress. Under such conditions metamorphic porosity comprises grain boundary tubules and bubbles together with continuously generated (and healed) microfractures. Deformation results in significant interconnected porosity and hence enhanced permeability. Lithologically and structurally controlled permeability variations may cause effective fluid channelling.Simple Rayleigh-Darcy modelling of a uniformly permeable, crustal slab shows that convective instability of metamorphic fluid is expected at the permeabilities suggested for the high Pf metamorphic conditions. Complex, large-scale convective cells operating in overpressured, but capped systems may provide a satisfactory explanation for the large fluid/rock ratios and extensive mass transport demonstrated for many low- and medium-grade metamorphic environments. Such large-scale fluid circulation may have important consequences for heat transfer in and the thermal evolution of metamorphic belts.

Notizen: Hydrothermal synthesis of Fe-pum-pellyites was conducted using high pressure cold-seal apparatus and solid oxygen buffering techniques at temperatures between 250°C and 550°C and 2.0–9.1 kbar Pfluid. Fe-pumpellyites were synthesized from partially crystalline gel mixtures of compositions: 4CaO - 2.1Al2O3_1.5FeO - 0.3MgO - 6SiO2 (II) and 3CaO - 1.5 Al2O3 - 2.7FeO - 0.3MgO - 6SiO2 (III) in the presence of excess H2O at Pfluid of 5–9.1 Kbar, temperatures between 275°C and 325°C, and fO2 defined by the QFM and HM buffers; for both of these compositions (II and III), the condensed synthetic run products included minor 7Å chlorite ± garnet ± Fe-oxide. The cell dimensions and aggregate refractive index (a= 19.13(2)Å, b= 5.940(4)Å, c= 8.847(5)Å, ±= 97.37(6)±, and n= 1.702(2)) of the pum-pellyite synthesized from the bulk composition II mix are compatible with those of natural pumpellyites containing similar total Fe contents. Attempts at synthesizing Fe-pumpellyites from a Mg-free bulk composition were not successful; these results are consistent with the total absence of natural Mg-free pumpellyites.The higher temperature, higher oxygen fugacity assemblages of the equivalent bulk compositions (II and III) consist of epidote ± minor amounts of chlorite, garnet, quartz, hematite, and magnetite. The results of these synthesis experiments accord with the mineral parageneses observed in low-grade metabasites which imply that Fe-pumpellyites are replaced by epidote with increasing temperature and/or fO2 and that Fe3+ is preferentially partitioned into epidote with respect to coexisting pum-pellyite. In addition, these synthesis experiments indicate that Fe-bearing pumpellyites crystallize at and are stable to lower temperatures than more aluminous pumpellyites—a result also consistent with natural systems.

Notizen: Oxide–sulphide–Fe–Mg–silicate and titanite–ilmenite textures as well as their mineral compositions have been studied in felsic and intermediate orthogneisses across an amphibolite (north) to granulite facies (south) traverse of lower Archean crust, Tamil Nadu, south India. Titanite is limited to the amphibolite facies terrane where it rims ilmenite or occurs as independent grains. Pyrite is widespread throughout the traverse increasing in abundance with increasing metamorphic grade. Pyrrhotite is confined to the high-grade granulites. Ilmenite is widespread throughout the traverse increasing in abundance with increasing metamorphic grade and occurring primarily as hemo-ilmenite in the high-grade granulite facies rocks. Magnetite is widespread throughout the traverse and is commonly associated with ilmenite. It decreases in abundance with increasing metamorphic grade. In the granulite facies zone, reaction rims of magnetite + quartz occur along Fe–Mg silicate grain boundaries. Magnetite also commonly rims or is associated with pyrite. Both types of reaction rims represent an oxidation effect resulting from the partial subsolidus reduction of the hematite component in ilmenite to magnetite. This is confirmed by the presence of composite three oxide grains consisting of hematite, magnetite and ilmenite. Magnetite and magnetite–pyrite micro-veins along silicate grain boundaries formed over a wide range of post-peak metamorphic temperatures and pressures ranging from high-grade SO2 to low-grade H2S-dominated conditions. Oxygen fugacities estimated from the orthopyroxene–magnetite–quartz, orthopyroxene–hematite–quartz, and magnetite–hematite buffers average 2.5 log units above QFM. It is proposed that the trends in mineral assemblages, textures and composition are the result of an external, infiltrating concentrated brine containing an oxidizing component such as CaSO4 during high-grade metamorphism later acted upon by prograde and retrograde mineral reactions that do not involve an externally derived fluid phase.

Notizen: Silica-undersaturated, sapphirine-bearing granulites occur in a large number of localities worldwide. Such rocks have historically been under-utilized for estimating P–T evolution histories because of limited experimental work, and a consequent poor understanding of the topology and P–T location of silica-undersaturated mineral equilibria. Here, a calculated P–T projection for sapphirine-bearing, silica-undersaturated metapelitic rock compositions is constructed using THERMOCALC for the FeO-MgO-Al2O3-SiO2 (FMAS) and KFMASH (+K2O + H2O) chemical systems, allowing quantitative analysis of silica-undersaturated mineral assemblages. This study builds on that for KFMASH sapphirine + quartz equilibria [Kelsey et al. (2004) Journal of Metamorphic Geology, vol. 22, pp. 559–578]. FMAS equilibria are significantly displaced in P–T space from silicate melt-bearing KFMASH equilibria. The large number of univariant silica-undersaturated KFMASH equilibria result in a P–T projection that is topologically more complex than could be established on the basis of experiments and/or natural assemblages. Coexisting sapphirine and silicate melt (with or without corundum) occur down to c. 900 °C in KFMASH, some 100 °C lower than in silica-saturated compositions, and from pressures of c.≤1 to ≥12 kbar. Mineral compositions and composition ranges for the calculated phases are consistent with natural examples. Bulk silica has a significant effect on the stability of sapphirine-bearing assemblages at a given P–T, resulting in a wide variety of possible granulite facies assemblages in silica-undersaturated metapelites. Calculated pseudosections are able to reproduce many naturally occurring silica-undersaturated assemblages, either within a single assemblage field or as the product of a P–T trajectory crossing several fields. With an understanding of the importance of bulk composition on sapphirine stability and textural development, silica-undersaturated assemblages may be utilized in a quantitative manner in the detailed metamorphic investigation of high-grade terranes.

Notizen: Several petrographic studies have linked accessory monazite growth in pelitic schist to metamorphic reactions involving major rock-forming minerals, but little attention has been paid to the control that bulk composition might have on these reactions. In this study we use chemographic projections and pseudosections to argue that discrepant monazite ages from the Mount Barren Group of the Albany–Fraser Orogen, Western Australia, reflect differing bulk compositions. A new Sensitive High-mass Resolution Ion Microprobe (SHRIMP) U–Pb monazite age of 1027 ± 8 Ma for pelitic schist from the Mount Barren Group contrasts markedly with previously published SHRIMP U–Pb monazite and xenotime ages of c. 1200 Ma for the same area. All dated samples experienced identical metamorphic conditions, but preserve different mineral assemblages due to variable bulk composition. Monazite grains dated at c. 1200 Ma are from relatively magnesian rocks dominated by biotite, kyanite and/or staurolite, whilst c. 1027 Ma grains are from a ferroan rock dominated by garnet and staurolite. The latter monazite population is likely to have grown when staurolite was produced at the expense of garnet and chlorite, but this reaction was not intersected by more magnesian compositions, which are instead dominated by monazite that grew during an earlier, greenschist facies metamorphic event. These results imply that monazite ages from pelitic schist can vary depending on the bulk composition of the host rock. Samples containing both garnet and staurolite are the most likely to yield monazite ages that approximate the timing of peak metamorphism in amphibolite facies terranes. Samples too magnesian to ever grow garnet, or too iron-rich to undergo garnet breakdown, are likely to yield older monazite, and the age difference can be significant in terranes with a polymetamorphic history.

Notizen: Fan-shaped polycrystalline staurolite porphyroblasts, 3–4 cm in length and 0.5 cm in width, occur together with centimetre-sized euhedral prismatic staurolite porphyroblasts in pelitic schists of the Littleton Formation on the western overturned limb of the Bolton syncline in eastern Connecticut. The fans consist of intergrown planar splays of [001] elongated prisms, which are crudely radial from a single apex. The apical angles of the radial groupings range up to 70°. The orientations of the individual staurolite prisms are related by a rigid rotation about an axis perpendicular to the fan plane. The zone axes [001] always lie in the plane of the fan. Although the angle between the [100] zone axes of the individual prisms is uniform in each fan, it ranges from +30° to −30° in different fans. Internally, the fans display: (i) remnants of a passively captured Si foliation defined by disc-shaped quartz blebs (type 1 inclusions) and layers of very fine carbonaceous material and tabular ilmenite platelets; (ii) bent staurolite blades and undulose extinction along low-angle (010) subgrain boundaries near the apex of the fans; (iii) wedge-shaped dilatational zones containing equigranular inclusion-free quartz, mica and staurolite, and (iv) growth-related quartz inclusion trails roughly perpendicular to a crystal face (type 2 inclusions). The Si inclusion trails are typically perpendicular to the fan surface, radiate parallel to the blades, and show little to no curvature except at the very edge of the fans where they abruptly curve through nearly 90° into parallelism with an external Se foliation. Careful examination of the three-dimensional geometry of fans based on U-stage measurements, serial sections and two-circle optical goniometric measurements permits a detailed reconstruction of their sequential development. The origin of a fan involves limited intracrystalline deformation and brittle crack dilation, spalling, rotation, and growth of small marginal fragments and of new staurolite along wedge-shaped zones along the Si inclusion surfaces. Fans preferentially develop in porphyroblasts in which Si is subparallel to the 010 cleavage. These internal features reflect the rotation and deformation of a brittle porphyroblast relative to syn-growth shear stresses.

Notizen: Detailed microtextural observations and bulk chemical analysis were undertaken on a garnet-pyroxenite nodule within retrograde eclogites from the NE Sulu ultrahigh-pressure metamorphic (UHPM) terrane. The results suggest that the protolith was a cumulate from a gabbroic body. The nodule consists primarily of coarse clinopyroxene grains with a very high content of the Ca-Tschermakite molecule. Microscopic observations and back-scattered electron images (BSE) demonstrate a complicated intergrowth of clinopyroxene, garnet and ilmenite, which represents the peak metamorphic assemblage. The primary clinopyroxene grains are armoured with a thin garnet corona up to 0.5 mm wide that forms an interconnected network. Within the clinopyroxene grains, four sets of garnet lamellae are distributed along crystallographic planes; locally, a vermicular intergrowth of garnet and diopside is developed. Besides the garnet, parallel arrays of ilmenite blebs are common within the clinopyroxene. Hydrous minerals such as amphibole, zoisite and titanite formed at later stages, and replaced diopside, garnet and ilmenite respectively. The P–T conditions determined for the formation of the garnet lamellae indicate that the garnet pyroxenite experienced UHP metamorphism at the same peak P–T condition as its host eclogite. The very high Ca-Tschermakite content (31–34 mol.%) of the primary clinopyroxene indicates crystallization at about 9–17 kbar and 1250–1450 °C, and together with the microtextural observations, suggests that the protolith of the garnet pyroxenite was a cumulate from a former gabbroic body, in which case, the host eclogite might represent the gabbroic body.

Notizen: Thermodynamic calculations in petrology are generally performed at pressures and temperatures beyond the standard state conditions. Accurate prediction of mineral equilibria therefore requires knowledge of the heat capacity, thermal expansion and compressibility for the minerals involved. Unfortunately, such data are not always available. In this contribution we present a data set to estimate the heat capacity, thermal expansion and compressibility of mineral end-members from their constituent polyhedra, based on the premise that the thermodynamic properties of minerals can be described by a linear combination of the fractional properties of their constituents. As such, only the crystallography of the phase of interest needs to be known. This approach is especially powerful for hypothetical mineral end-members and for minerals, for which the experimental determination of their thermodynamic properties is difficult. The data set consists of the properties for 35 polyhedra in the system K–Na–Ca–Li–Be–Mg–Mn–Fe–Co–Ni–Zn–Al–Ti–Si–H, determined by multiple linear regression analysis on a data set of 111 published end-member thermodynamic properties. The large number of polyhedra determined allows calculation of a much larger variety of phases than was previously possible, and the choice of constituents together with the large number of thermodynamic input data results in estimates with associated uncertainty of generally 〈5%. The quality of the data appears to be sufficiently accurate for thermodynamic modelling as demonstrated by modelling the stability of margarite in the CASH system and the position of the talc–staurolite–chloritoid–pyrope absent invariant point in the KMASH system. In both cases, our results overlap within error with published equivalents.

Notizen: The prograde pressure–temperature (P–T) path for the complexly polydeformed Proterozoic Broken Hill Block (Australia) has been reconstructed through detailed structural analysis in conjunction with calculation of compositionally specific P–T pseudosections of pelitic rock units within a high-temperature shear zone that formed early in the tectonic evolution of the terrane. Whilst the overall P–T path for the Broken Hill Block has been interpreted to be anticlockwise, the prograde portion of this path has been unresolved. Our results have constrained part of this prograde path, showing an early heating event (M1) at P–T conditions of at least c. 600 °C and c. 2.8–4.2 kbar, associated with an elevated geothermal gradient (c. 41–61 °C km−1). This event is interpreted to be the result of rifting at c. 1.69–1.67 Ga, or at c. 1.64–1.61 in the Broken Hill Block. Early rifting was followed by an episode of lithospheric thermal relaxation and burial, during which time sag-phase sediments of the upper Broken Hill stratigraphy (Paragon Group) were deposited. Following sedimentation, a second tectonothermal event (M2/D2) occurred. This event is associated with peak low-pressure granulite facies metamorphism (c. 1.6 Ga) and attained conditions of at least 740 °C at c. 5 kbar. A regionally pervasive, high-temperature fabric (S2) developed during the M2/D2 event, and deformation was accommodated along lithology-parallel, high-temperature shear zones. The larger-scale deformation regime (extensional or shortening) of this event remains unresolved. The M2/D2 event was terminated by intense crustal shortening during the Olarian Orogeny, during which time the first mappable folds within the Broken Hill Block developed.

Notizen: A calibration is presented for an activity–composition model for amphiboles in the system Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–O (NCFMASHO), formulated in terms of an independent set of six end-members: tremolite, tschermakite, pargasite, glaucophane, ferroactinolite and ferritschermakite. The model uses mixing-on-sites for the ideal-mixing activities, and for the activity coefficients, a macroscopic multicomponent van Laar model. This formulation involves 15 pairwise interaction energies and six asymmetry parameters. Calibration of the model is based on the geometrical constraints imposed by the size and shape of amphibole solvi inherent in a data set of 71 coexisting amphibole pairs from rocks, formed over 400–600 °C and 2–18 kbar. The model parameters are calibrated by combining these geometric constraints with qualitative consideration of parameter relationships, given that the data are insufficient to allow all the model parameters to be determined from a regression of the data. Use of coexisting amphiboles means that amphibole activity–composition relationships are calibrated independently of the thermodynamic properties of the end-members. For practical applications, in geothermobarometry and the calculation of phase diagrams, the amphibole activity–composition relationships are placed in the context of the stability of other minerals by evaluating the properties of the end-members in the independent set that are in internally consistent data sets. This has been performed using an extended natural data set for hornblende–garnet–plagioclase–quartz, giving the small adjustments necessary to the enthalpies of formation of tschermakite, pargasite and glaucophane for working with the Holland and Powell data set.

Notizen: Integrated petrological and structural investigations of eclogites from the eclogite zone of the Voltri Massif (Ligurian Alps) have been used to reconstruct a complete Alpine P–T deformation path from burial by subduction to subsequent exhumation. The early metamorphic evolution of the eclogites has been unravelled by correlating garnet zonation trends with the chemical variations in inclusions found in the different garnet domains. Garnet in massive eclogites displays typical growth zoning, whereas garnet in foliated eclogites shows rim-ward resorption, likely related to re-equilibration during retrogressive evolution. Garnet inclusions are distinctly different from core to rim, consisting primarily of Ca-, Na/Ca-amphibole, epidote, paragonite and talc in garnet cores and of clinopyroxene ± talc in the outer garnet domains. Quantitative thermobarometry on the inclusion assemblages in the garnet cores defines an initial greenschist-to-amphibolite facies metamorphic stage (M1 stage) at c. 450–500 °C and 5–8 kbar. Coexistence of omphacite + talc + katophorite inclusion assemblage in the outer garnet domains indicate c. 550 °C and 20 kbar, conditions which were considered as minimum P–T estimates for the M2 eclogitic stage. The early phase of retrograde reactions is polyphase and equilibrated under epidote–blueschist facies (M3 stage), characterized by the development of composite reaction textures (garnet necklaces and fluid-assisted Na-amphibole-bearing symplectites) produced at the expense of the primary M2 garnet-clinopyroxene assemblage. The blueschist retrogression is contemporaneous with the development of a penetrative deformation (D3) that resulted in a non-coaxial fabric, with dominant top-to-the-N sense of shear during rock exhumation. All of that is overprinted by a texturally late amphibolite/greenschist facies assemblages (M4 & M5 stages), which are not associated with a penetrative structural fabric. The combined P–T deformation data are consistent with an overall counter-clockwise path, from the greenschist/amphibolite, through the eclogite, the blueschist to the greenschist facies. These new results provide insights into the dynamic evolution of the Tertiary oceanic subduction processes leading to the building up of the Alpine orogen and the mechanisms involved in the exhumation of its high-pressure roots.

Notizen: One of the proximate results of forest fragmentation, and a cause of continued microenvironmental change and exacerbation of ecological problems, is increased invasions by weedy plant species. One such example is Alliaria petiolata (Brassicaceae), a serious pest threatening much of eastern North America. Alliaria petiolata impedes mitigation of fragmentation and restoration efforts because it tends to outcompete and possibly extirpate much of the native understory species on localized scales. As part of a strategy to address the problems of fragmented habitats, an experiment was conducted to determine whether Sanguinaria canadensis (Papaveraceae) could outcompete A. petiolata. Using an additive design, I transplanted S. canadensis at densities of 0, 1, 2, 3, 5, 7, 9, 11, 15, and 20 ramets/m2 in 1997 and allowed them to interact with initial A. petiolata densities of 128 seedlings and 31 rosettes/m2. As of 2000, multivariate analyses of variance with repeated measures and simple analyses of variance indicated that initial S. canadensis densities of as little as 5 ramets/m2 suppressed A. petiolata. Initial S. canadensis densities of 9 and 11 ramets/m2 resulted in the lowest numbers of late-spring seedlings, numbers and sizes of year 1 and 2 rosettes, numbers and gross areas of stem leaves, numbers of flowering individuals, number of flowers, number of fruits (siliques), and height at flowering. While it remains to be tested whether this will continue and if the reestablishment of S. canadensis will help reassemble forest ecosystems, the experiments indicated that transplanting S. canadensis was effective at mitigating the spread of A. petiolata.

Notizen: Canebrakes are dense stands of Arundinaria gigantea (Walt.) Muhl. that covered large areas of the southeastern North America. With agricultural development, canebrakes were quickly converted to crop and pastureland and now occur only in small, isolated patches. There is growing interest in the use of A. gigantea and other temperate bamboo species in riparian and floodplain revegetation in North America, but lack of detailed information on propagation and management of woody perennial grasses hinders reestablishment activities. Our study assesses the influence of nutrient and woodchip mulch amendments on survival and growth of A. gigantea transplanted as part of a riparian restoration project in central Kentucky. After two growing seasons, culm number (aboveground stems) increased 4-fold and extent of transplanted clumps expanded 26-fold. The survival rate of transplanted cane clumps was 98%. Hardwood chip mulch significantly increased the emergence of new culms, culm height growth, and clump area. Composted manure, applied at a rate that contributed a similar mass of organic matter as the hardwood mulch, also significantly increased new culm number and clump area. Our findings demonstrate that addition of manure or hardwood mulch can significantly enhance aboveground production of A. gigantea transplants. However, survival and initial growth of untreated clumps were also adequate in this study. It appears that careful site selection, transplantation, and site maintenance may be sufficient to ensure A. gigantea establishment on many sites. Practitioners should assess soil drainage, water stress, and fertility along with herbaceous competition and incidence of overbank flooding before determining the necessity of organic amendments to supplement establishment of A. gigantea or other woody grasses for riparian restoration.

Notizen: Constraints to grassland and open forest restoration (e.g., poor seed sources, yearly variation in establishment, and the persistence of weeds) necessitate the development of innovative methods to restore bunchgrass communities. We assessed the use of two native bunchgrass transplants, Bluebunch wheatgrass (Pseudoroegneria spicata) and Spreading needlegrass (Achnatherum richardsonii), for restoration within thinned montane forest communities of southeastern British Columbia, Canada. Fall and spring plantings were examined, either with or without glyphosate treatments to Pinegrass (Calamagrostis rubescens) neighbors. Calamagrostis rubescens is abundant in grassland affected by tree encroachment and may limit transplant establishment. Bunchgrass survival was positively associated (p 〈 0.05) with transplant size. Although P. spicata survival was greater (p 〈 0.01) with fall (81%) than with spring (44%) planting, survival of A. richardsonii was greater (p 〈 0.01) when planted in the spring (68 vs. 23%). Reduction of C. rubescens led to a relatively small but significant increase (p 〈 0.05) in bunchgrass survival by 7%. The summer after planting, changes in transplant tiller number varied by bunchgrass species, planting season, and treatment of neighboring C. rubescens. Removal of neighboring C. rubescens generally increased the number of tillers (or reduced tiller loss) but only within fall-planted A. richardsonii and spring-planted P. spicata. Both A. richardsonii and P. spicata transplants have potential for understory restoration within thinned montane forests, particularly using larger individuals, although to maximize survival, these species should be planted in the spring and fall, respectively. Reduction of C. rubescens may also enhance transplant survival and in some cases growth.

Notizen: Carolina bays are depression wetlands of high conservation value that occur across the Southeastern Coastal Plain of the United States. Venus flytrap (Dionaea muscipula) is one rare carnivorous plant that grows in open habitats on the rims of Carolina bays. Without frequent burning, vegetation on bay rims becomes dominated by evergreen shrubs and Venus flytrap populations decline. This project examined the utility of mechanical mowing, soil clearing, transplanting, and seeding as an approach to restoring populations of Venus flytraps when fire is precluded. Mowing of patches on bay rims produced open sites with little ground-layer vegetation. After two growing seasons, adult Venus flytraps transplanted to mowed patches showed high survivorship and relatively high leaf number/plant. Suppressed Venus flytraps existing on-site quickly initiated growth in response to mowing. These volunteers and the transplants had higher flowering percentages than plants in reference populations. Seeds of Venus flytraps were scattered in mowed and cleared plots. Seedling establishment was low, but seedlings persisted into the second growing season. Mowing created suitable habitat for growth and flowering of adult Venus flytraps and facilitated establishment of two other carnivorous species, Sundew (Drosera capillaris) and Bladderwort (Utricularia subulata). But, mowing and clearing also facilitated invasion by four species of grasses and rushes; evergreen shrubs resprouted quickly after mowing. Maintaining persistent openings by mowing the rims of Carolina bays will be an ongoing challenge due to availability of potential invaders and rapid regrowth of shrubs.

Notizen: Native plant establishment is limited by harsh environmental conditions in areas affected by tephra deposition following volcanic eruptions. Late-successional species might be lacking even decades after the disturbance. We assessed the effectiveness of pine-bark mulch, a by-product of sustainable timber production in the study area, in promoting the establishment and survival of a late-successional species (Pinus pseudostrobus) and a nitrogen-fixing legume (Lupinus elegans). We established a factorial experiment in areas covered with tephra during the eruption of the Paricutín volcano in the state of Michoacán, Mexico. After 1 year, P. pseudostrobus survival was significantly higher (p 〈 0.001) in plots with pine-bark mulching (46.5%) than in plots without mulching (21.8%). After 2 years, surviving pines with mulching were significantly taller (p= 0.03) than pines without mulching (45.3 ± 3.8 cm and 31.2 ± 3.7 cm, respectively). Lupinus elegans plants survived longer when grown in plots with pine-bark mulching than without mulching. Mulching reduced tephra temperatures during the dry season (when temperatures can reach up to 58°C 4 cm below the surface of bare tephra). Lupinus elegans plants were affected by herbivory by small rodents, run-off, and frost at the end of the growing season. Our results suggest that mulching can ameliorate harsh environmental conditions on sites covered with tephra while incorporating a by-product of sustainable forestry into restoration practice.

Notizen: Bracken (Pteridium aquilinum) is a major weed of seminatural vegetation in Great Britain, as in many other countries. As a consequence, large areas have been subject to control with the intention of restoring the former vegetation. The use of aerial spraying with asulam, a narrow spectrum, carbamate herbicide, has become a common method of control. However, its long-term efficacy has not been assessed in terms of either controlling the bracken or in producing suitable restored habitats. This study undertook such an assessment by comparing the results of a 2002 survey of the sites subject to bracken control by aerial spraying of asulam with previous (1990/1991 and 1994) surveys of the same sites. This showed that a single application of asulam was effective in eradicating bracken (〈1% cover remaining) on a third of sites. However, on 10% of the sites, the bracken had regenerated completely (cover 〉80%) and on the remainder it was still present in patches (〉20% of quadrats), often at high density. More than half the sprayed sites had seen good recovery of moorland vegetation, the target of the restoration, because they were now classified as having upland heathland vegetation within the National Vegetation Classification. Considerable amounts of bracken control are grant aided as part of agri-environment schemes. These schemes should be adapted to encourage good practice, namely, intensive follow-up treatment by spraying any emerging fronds, and to encourage treatment of previously sprayed areas rather than spraying of new areas in order to protect previous investment of grant aid.

Notizen: Invasions of North American grasslands by Spotted knapweed (Centaurea maculosa Lam.) are mediated in part by Spotted knapweed root exudation of (±)-catechin, a potent phytotoxin. Residual soil (±)-catechin may interfere with reestablishment of native grassland species even after Spotted knapweed populations are controlled. Grassland species that are resistant to (±)-catechin may be more successful for restoration of areas infested by Spotted knapweed. We evaluated the (±)-catechin resistance of 23 grassland species by measuring the effects of seven (±)-catechin concentrations (0–4.0 mg/mL) on seed germination, seedling root and shoot elongation, and seedling mortality. (±)-Catechin treatments were chosen to reflect the range of observed Spotted knapweed field soil (±)-catechin concentrations. Inhibition of root elongation was the strongest and most common effect of (±)-catechin treatment. High (±)-catechin concentrations reduced mean root lengths of 5 of the species by more than 75% and another 10 species by more than 55%. Experimentally derived concentrations needed to reduce root length by 50% (EC50), an indicator of (±)-catechin resistance, ranged from 0.43 mg/mL ± 0.30 SE to greater than 4.0 mg/mL among species. Eight species with EC50s greater than 3.0 mg/mL were identified as resistant to (±)-catechin and are likely suitable for revegetation of Spotted knapweed–infested areas. (±)-Catechin resistance was positively correlated with mean seed mass, suggesting that seed carbohydrate reserves may allow seedlings to detoxify (±)-catechin, develop barriers to (±)-catechin exposure, or sustain a positive growth rate, despite (±)-catechin-induced cell death. Future efforts to identify allelochemical-resistant grassland species should focus on large-seeded species.

Notizen: In plant conservation, restoration (the augmentation or reestablishment of an extinct population or community) is a valuable tool to mitigate the loss of habitat. However, restoration efforts can result in the introduction of novel genes and genotypes into populations when plant materials used are not of local origin. This movement is potentially important because many plant species are subdivided into populations that are adapted to local environmental conditions. Here we focus on genetic concerns arising from ongoing restoration efforts, where often little is known about “How local is local?” (i.e., the geographic or environmental scale over which plant species are adapted). We review the major issues regarding gene flow and local adaptation in the restoration of natural plant populations. Finally, we offer some practical, commonsense guidelines for the consideration of genetic structure when restoring natural plant populations.

Notizen: Ecological restoration often relies on the use of expert opinion to make management decisions in the face of uncertainty. The quantification of expert opinion can be difficult, especially when more than one expert is consulted and experts are not in agreement. Decision analysis can provide a framework to systematically deconstruct a complex problem and provide greater objectivity to restoration decisions. We utilized decision analysis techniques to identify restoration objectives and to quantify expert opinions to prioritize restoration activities at 112 prairie openings in the Edge of Appalachia Preserve in southern Ohio, U.S.A. We first created an objectives hierarchy to model how decision-makers decide which prairies to manage. We then determined how to measure each component of the hierarchy and sampled all prairies for percent woody cover, geology, indicator species index (an index of plant species richness), slope, aspect, and distance to nearest prairie. We modeled seven different experts’ preferences for managing prairies with varying values for each of these ecological measures. We then interviewed the same decision-makers to determine relative weights for each component of the objectives hierarchy using trade-off analysis. By combining the weights, preference relationships, and sampling data, we were able to rank each prairie and management unit based on its management priority. Experts had similar preferences except for the measure of distance to nearest prairie. We found that decision-makers gave different weights to each of the different components of the hierarchy. Generally, experts weighted percent woody cover, indicator species index, and geology more highly than slope, aspect, and distance to nearest prairie. Despite these differences, priorities for management, once all factors were weighted and combined, were similar.

Notizen: The Karner blue butterfly (KBB) (Lycaeides melissa samuelis), a federally listed species, has historically been a component of barren and savannah ecosystems in the northeastern and midwestern United States. In New York, it now occurs primarily on managed, early-successional sites such as power line corridors (utility rights-of-way) from Albany to Glens Falls. Blue lupine (Lupinus perennis), the exclusive larval food source of the KBB, has been suggested to be the most limiting factor for the butterfly within the eastern portion of its range. Power line corridor management maintains early-successional habitats by suppressing the regrowth of woody species, creating potentially important habitat for the conservation and restoration of the KBB complex. This research compared the effects of several vegetation-clearing methods on Blue lupine populations and associated communities of nectar species for KBB over an 8-year period. Methods evaluated differed in intensity (annual, 4-, or 8-year intervals) and type (herbicide or mechanical). Blue lupine and plant community responses did not significantly differ among the treatment types applied to the power line corridors. However, Blue lupine cover, clump size, and density of stems per clump increased following the application of treatments in general. The number and cover of nectar species, total herbaceous cover, and species richness also responded positively to treatment overall. The percentage of non-native species temporarily increased following treatment but declined to near pre-treatment levels again as woody cover increased. Temporal changes in plant community composition were not related to management methods. The management tools assessed, mowing and herbicide application, will accomplish the goal of halting or reversing succession, maintaining critical habitat for the KBB in a landscape that provides little other suitable habitat.

Notizen: Replacement of perennial grasses with non-native annual grasses in California's Central Valley grasslands and foothills has increased deep soil water availability. Yellow starthistle (Centaurea solstitialis), a deep-rooted invasive thistle, can use this water to invade annual grasslands. Native perennial bunchgrasses, such as Purple needlegrass (Nassella pulchra), also use deep soil water, so there is an overlap in resource use between N. pulchra and C. solstitialis. Restoration of N. pulchra to annual grasslands could result in strong competitive interactions between N. pulchra and C. solstitialis, which may reduce survival, growth, and reproduction of the invader. The strength of this competitive interaction can increase as N. pulchra plants mature, increase in size, and develop more extensive root systems. We studied how the size of N. pulchra affected the success of C. solstitialis invasion over 2 years. We allowed C. solstitialis seed to fall naturally into plots containing N. pulchra plants. For each plot, we measured the number of C. solstitialis seedlings and mature plants, as well as C. solstitialis biomass and seedhead production. In both years of the study, C. solstitialis number, biomass, and seedhead production declined significantly as N. pulchra size increased. However, even C. solstitialis grown with the largest N. pulchra plants produced some seed, especially during the higher rainfall year. We conclude that restoration plantings with larger, established N. pulchra plants will be more resistant to invasion by C. solstitialis than young N. pulchra plantings, but site management must continue as long as a C. solstitialis seed source is present.

Notizen: A study was conducted to evaluate the long-term effects of biosolids amendment on restoration of disturbed sagebrush steppe habitat in northwestern Colorado. Twenty-four years after biosolids amendment, soil fertility and plant community development were studied in replicated plots receiving various biosolids amendments on two different substrates. The two substrates used were a subsoil, determined to have low initial fertility, and a topsoil over retorted shale substrate, determined to have relatively high initial fertility. Results suggest that biosolids amendments have long-lasting effects on soil fertility and plant community composition, but these effects vary between the two substrates that were utilized. Within the plots established on subsoil, the long-term effect of biosolids was a reduction in plant species diversity and dominance by perennial grasses. On the topsoil substrate, there was a decrease in perennial grasses and an increase in shrub dominance with increasing biosolids. Results demonstrate the importance of considering initial soil conditions, seed mixture, and biosolids application rate when using biosolids for restoration of disturbed sagebrush steppe habitat. The long-term effects of the biosolids treatments at this site demonstrate the need to consider restoration treatment effects over longer and more ecologically meaningful time frames.

Notizen: Non-native fish generally cause native fish decline, and once non-natives are established, control or elimination is usually problematic. Because non-native fish colonization has been greatest in anthropogenically altered habitats, restoring habitat similar to predisturbance conditions may offer a viable means of non-native fish control. In this investigation we identified habitats favoring native over non-native fish in a Mojave Desert oasis (Ash Meadows) and used this information to restore one of its major warm water spring systems (Kings Pool Spring). Prior to restoration, native fishes predominated in warm water (25–32°C) stream and spring-pool habitat, whereas non-natives predominated in cool water (≤23°C) spring-pool and marsh/slack water habitat. Native Amargosa pupfish (Cyprinodon nevadensis) and Ash Meadows speckled dace (Rhinichthys osculus nevadensis) inhabited significantly faster mean water column velocities (MWCV) and greater total depth (TD) than non-native Sailfin molly (Poecilia latipinna) and Mosquitofish (Gambusia affinis) in warm water stream habitat, and Ash Meadows speckled dace inhabited significantly faster water than non-natives in cool water stream habitat. Modification of the outflow of Kings Pool Spring from marsh to warm water stream, with MWCV, TD, and temperature favoring native fish, changed the fish composition from predominantly non-native Sailfin molly and Mosquitofish to predominantly Ash Meadows pupfish. This result supports the hypothesis that restoring spring systems to a semblance of predisturbance conditions would promote recolonization of native fishes and deter non-native fish invasion and proliferation.

Notizen: Rainforest fragmentation and creek degradation are major problems on the Atherton Tablelands in North Queensland. Lake Barrine and Wooroonooran National Parks are separated by a 1.5-km length of Toohey's Creek which has been cleared except for small remnant rainforest patches. The creek has been fenced and replanted to create a corridor between the two national parks. The aim of this study was to monitor the success of the corridor in providing habitat for rainforest birds. Avian communities were monitored in the corridor and in adjacent rainforest sites using point counts over the period of reestablishment of a continuous rainforest canopy. In terms of bird community composition, within 3 years of planting, the replanted sites were on a trajectory toward the rainforest sites. Although specialist rainforest species were not yet found in the plantings, after 3 years those species which mainly inhabit rainforest but also utilize edges and riparian strips were found in similar numbers in the plantings and in the small remnant patches along the corridor. Frugivorous species were quite abundant even in the youngest plantings. Thus, replanting of rainforest trees along Toohey's Creek has begun to provide habitat for some rainforest birds. It also shows good potential to act as a corridor to connect the previously isolated patches of rainforest for these species and to develop in habitat complexity as the frugivorous birds bring in rainforest plant species from nearby areas.

Notizen: Many semiarid rangelands in the Great Basin, U.S.A., are shifting dominance to woody species as a consequence of land degradation including intense livestock grazing and fire suppression. Whereas past rehabilitation efforts in Big sagebrush (Artemisia tridentata) steppes removed the shrub and added introduced forage grasses to successfully shift communities from shrublands to grasslands, current consensus is that native species should be included in restoration projects and that retention of some woody plants is desirable. We examined the potential for interseeding grasses into dense shrub communities as a precursor to thinning shrubs and releasing grasses from shrub interference. We compared seedling establishment of the native grass, Bluebunch wheatgrass (Pseudoroegneria spicata), with that of the Eurasia grass, Crested wheatgrass (Agropyron desertorum), in dense Ar. tridentata stands. Shrubs may play an important role as nurse plants for seedling establishment (reduced solar radiation, “island of fertility” effect) but result in highly contrasting light environments and root interference for seedlings. In experimental plots, we examined effects of Ar. tridentata shade levels (0, 40, 70, and 90% reduction of solar radiation) and initial root exclusion (present/absent) on the establishment and growth of P. spicata and Ag. desertorum seedlings. With this design we evaluated the interference effects of Ar. tridentata on the two grasses and identified the most beneficial microsites for grass restoration in Ar. tridentata–dominated communities. We predicted seedling survival and growth to be greater under moderate shade (40% reduction) and limited root competition than under no or strong shade conditions (0 and 90%) and unrestricted root interactions. Fifty to 85% of the P. spicata and Ag. desertorum seedlings survived the dry summer months of 1995 and 1996 and the intervening winter. Neither shading nor root exclusion from Ar. tridentata affected final seedling survival of either species. Seedling biomass of both grass species was negatively affected by initial root interactions with Ar. tridentata. However, the analysis of seedling biomass variability (coefficient of variation) indicated that in all shade and root-exclusion treatments, some seedlings of both species developed to large individuals to survive in Ar. tridentata–dominated rangelands. Thus, the use of interseeding techniques shows promise for restoring herbaceous species in dense Ar. tridentata stands and should be given further consideration when shrub retention is an important consideration.

Notizen: Preventing and controlling exotic plants remains a key challenge in any ecological restoration, and most efforts are currently aimed at local scales. We combined local- and landscape-scale approaches to identify factors that were most closely associated with invasion of riparian forests by exotic shrubs (Amur honeysuckle [Lonicera maackii] and Tatarian honeysuckle [L. tatarica]) in Ohio, U.S.A. Twenty sites were selected in mature riparian forests along a rural–urban gradient (〈1–47% urban land cover). Within each site, we measured percent cover of Lonicera spp. and native trees and shrubs, percent canopy cover, and facing edge aspect. We then developed 10 a priori models based on local- and landscape-level variables that we hypothesized would influence percent cover of Lonicera spp. within 25 m of the forest edge. To determine which of these models best fit the data, we used an information-theoretic approach and Akaike's information criterion. Percent cover of Lonicera was best explained by the proportion of urban land cover within 1 km of riparian forests. In particular, percent cover of Lonicera was greater in forests within more urban landscapes than in forests within rural landscapes. Results suggest that surrounding land uses influence invasion by exotic shrubs, and explicit consideration of land uses may improve our ability to predict or limit invasion. Moreover, identifying land uses that increase the risk of invasion may inform restoration efforts.

Notizen: The extent of impairment to some Appalachian watersheds from acid precipitation is so extreme that watershed scale analytical tools are needed to help guide cost-effective management decisions. The objective of this study was to develop a measure of the functional value of streams as potential areas for juvenile Brook trout recruitment. This measure, which we term “weighted potential recruitment area” (WPRA), is a function of the expected Brook trout spawning intensity and juvenile survivorship. Estimates of WPRA for each stream segment were then used to identify restoration priorities and optimal restoration programs in the upper Shavers Fork watershed in West Virginia, U.S.A. Using this approach, we determined that the watershed has lost nearly 80% of its historic juvenile recruitment potential as a result of acid precipitation. We also determined that of the 145 stream segments in the watershed, eight critical stream segments account for nearly 20% of the loss. The costs and ecological benefits of a series of five alternative restoration programs were then assessed using an ArcGIS model (Environmental Systems Research Institute, Redlands, CA, U.S.A.). This approach identified two “optimal” alternatives: (1) a low-cost, moderate-benefit approach that would use existing rail access to treat acidification in three critical headwater locations and (2) a high-cost, high-benefit approach that would use aerial limestone application to treat numerous acidic tributaries near their source. The measure of stream ecological value that we developed was effective in identifying critical restoration priorities and optimal restoration strategies in this watershed. A similar procedure could be used to guide watershed restoration decisions throughout the Appalachian region.

Notizen: Book reviews in this article:THE CHESA PHOTOGRAMMETRIC EXPERIMENT (Technical Publication

Notizen: The paper presents research and development at the Thematic Information Service of the Natural Environment Research Council (NERC) on the topic of integrated geographic information systems. The term integrated is used to describe the incorporation of vector digitised map data and raster scanned remotely sensed data within a single computational environment and with a single interface to the user. Point sampled and statistical data can also be handled by the system. The general structure and working of the Thematic Information Service (TIS) is described only to the extent that it is relevant to providing the background to the research or to highlighting why the specific approach described has been taken.

Notizen: A procedure for digital image correlation is described which is based on least squares window matching. The immediate aim is high precision parallax assessment, point transfer, and point measurement. Experiments and theory have confirmed the high accuracy potential of the method. By implementation of charge coupled device (CCD) video cameras in an analytical plotter, an experimental hardware and software configuration has been established with which the operational on line application of digital image correlation for conventional photogrammetric measuring tasks can be tested. First results of calibration and performance of the system are presented. They allow optimistic conclusions as to the further development and practical application of digital image processing in photogrammetry.

Notizen: Book review in this aticle:DESERTS AND ARID LANDS. Edited by F. El-Baz.IMAGES OF THE WORLD AN ATLAS OF SATELLITE IMAGERY AND MAPS. By C. Mueller-Wille with an interpretive supplement by R. M. Smith.ELEMENTS OF PHOTOGRAMMETRY. By P. R. Wolf.

Notizen: The essential features of equipment for mobile processing are outlined with reference to the development of small photographic laboratory vehicles for use in the Jield. The resulting air film processor, the Wainco Products Limited 392. is described and details are given of trials carried out to establish its performance for a range of tasks in both reconnaissance and survey. The tests cover the sensitometric and drying behaviour of several air films in current use and include an analysis of the dimensional stability o f j l m in the processor. Applications using direrent containers and eflectiveness in improvised situations are also described and possible future variants of the processor are suggested.

Notizen: This paper is concerned with a new technique (the terrestrial/photogrammetric (TP) technique) for the detection and compensation of systematic height errors in block aerial triangulation. The technique improves the height accuracy of such triangulation by reducing the original bridging distance, using new bands of corrected photogrammetric tie points as height control together with the original bands of the terrestrial (or ground) height control. A number of photogrammetric blocks with different characteristics and configurations have been tested in a comprehensive manner. The tests show that the TP technique gives consistent results over a wide range of circumstances and that it is a most effective, simple and inexpensive method for the compensation of systematic errors.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméCet article relate une technique nouvelle permettant de détecter et de compenser les erreurs altimétriques systématiques dans l'aérotriangulation par blocs: la technique terrestre/photogrammétrique (TP). Cette technique améliore la précision altimétrique de l'aérotriangulation en réduisant la distance de l'aérocheminement original, grâce à l'utilisation d'un canevas de points d'appuis altimétriques composés de points de liaison photogrammétriques corrigés, en supplément du canevas original de points d'appui altimétriques déterminés sur le terrain.On a essayé de manière approfondie un grand nombre de blocs dotés de caractéristiques et de configurations diverses. Les essais montrent que la technique TP fournit des résultats fiables dans un large éventail de circonstances et que c'est une méthode de compensation des erreurs systématiques efficace, simple et peu coûteuse.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungIm Artikel wird ein neues Verfahren behandelt (das terrestrisch-photogrammetrische Verfahren (TP)), das zur Aufdeckung und Kompensation system-atischer Höhenfehler in der Block triangulation dient. Es wird die Höhengenauigkeit durch Verkürzung der ursprünglichen Überbrückungsdistanz verbessert, indem neue Streifen korrigierter Verbindungspunkte als Höhenpasspunkte zusammen mit den ursprünglichen Reihen der terrestrischen Höhenpasspunkte verwendet werden. Eine Anzahl photogrammetrischer Blöcke unterschiedlicher Figur und Charakteristik wurde umfassend getestet. Die Tests zeigen, dass die TP-Methode konstante Ergebnisse für einen grossen Bereich van Möglichkeiten ergibt und dass es ein höchst effektives, einfaches und billiges Verfahren zur Eliminierung systematischer Fehler ist.

Notizen: The development of an automated photographic measuring system (APM) is described. A very accurate laser beam scanning microdensitometer is used to digitise the photographic plate and a series of on line computers analyses the data during scanning. The system is available as a national facility for United Kingdom astronomers and guest investigators.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn décrit un systéme automatisé de saisie de données sur cliché. Un microdensitométre à laser numérise la plaque photographique et les données sont analysées en temps réel par ordinateur. Le systeme est destiné aux astronomes du Royaume Uni et aux chercheurs y séjournant.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBeschreibung eines automatisierten photographischen Messsystems (APM). Ein hochgenaues Laser-Mikrodensitometer wird dabei zur Digitalisierung der Bilder benutzt, undeine Serie von On-line-Rechnern analysiert die Daten während der Abtastung. Das System steht für Astronomen im Vereinigten Königreich und anderen Forschern zur Verfügung.

Notizen: During June and July 1981, synthetic aperture radar imagery was acquired of selected sites in ten European countries as part of the European SAR 580 campaign. Evaluation of this imagery in the UK will be carried out by 18 approved experiments (out of 56 for Europe) when the processed data becomes available to investigators. To assist the evaluation process, a review is given of some recent research on applications of imaging radar in agricultural and urban areas. Research is described which considered the effects of terrain parameters and radar parameters on crop classification accuracy. The relative merits of a quantitative or a qualitative approach in classification of radar data are considered. Combined use of radar and Landsat data achieves a marked improvement in classification accuracy. The development of spatial filtering techniques may assist in the problem in urban areas resulting from the dependence of image tone on the relative alignment of ground features and radar look direction.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméPendant les mois dejuin et juillet 1981, on a, dans le cadre de la campagne européenne SAR 580, recueilli des données de radar imageur à synthèse d'ouverture sur des sites choisis dans une dizaine de pays d'Europe. Ces données seront évaluées au Royaume-Uni au moyen de 18 expériences ayant été acceptées (sur un total de 56 menées en Europe); ce travail commencera dès que les données une fois traitées seront distribuées aux chercheurs. Pour accompagner cette procédure d'evaluation, on fournit une analyse de quelques recherches récentes sur les applications de l'imagerie radar aux zones agricoles et urbaines.L'une de ces recherches prenait en compte les effets des paramètres liés au terrain sur l'exactitude de la classification des cultures. Les mérites réciproques des approches quantitatives et qualitatives dans la classification des données radar sont également examinés.Le recours à une combinaison de données radar et Landsat permet d'améliorer de manière significative l'exactitude de la classification. La mise en oeuvre des techniques de filtrage spatial peut aider à réduire, dans les zones urbaines, les conséquences néfastes sur la tonalité de l'image, d'objets au sol en alignement relatif avec la direction d'observation du radar.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungIm Juni und Juli 1981 erfolgten Radaraufnahmen mittels synthetischer Apertur von ausgewählten Gebieten in 10 europäischen Ländern als Teil der Europäischen SAR 580 Kampagne. Die Analyse dieser Aufzeichnungen wird im Vereinigten Königreich durch 18 (aus insgesamt 56 für Europa) bestätigte Experimente erfolgen, nachdem die Daten zur Verfügung stehen. Um den Analysenprozess zu unterstützen, wird ein Überblick über kürzliche Forschungen zu Radaraufzeichnungen in landwirtschaftlichen und städtischen Gebieten gegeben. Es werden auch Forschungen beschrieben, bei denen die Einflüsse von Geländeparametern auf die Genauigkeit der Ernteklassifizierung untersucht wurden. Der relative Wert eines quantitativen oder qualitativen Versuchs zur Klassifizierung von Radardaten wird abgeschätzt. Eine Kombination von Radarund Landsat-Daten ergibt eine merkliche Verbesserung bei Klassifizierungsgenauigkeit. Die Entwicklung von Verfahren der räumlichen Filterung kann von Wert bei städtischen Gebieten sein, weil es eine Abhängigkeit des Grauwertes von der relativen Ausdehnung von Geländecharakteristika und der Richtung der Radaraufnahme gibt.

Notizen: Some aspects of the XYZBLC suite of programs for aerial triangulation are described. The Ordnance Survey Bute block of photography at a scale of 1: 24000 is computed by independent models using XYZBLC. Three of the strips in the block are treated as a test block and are computed with different configurations of control. Conclusions are drawn with regard to the usefulness of height control doublets and other dense control configurations.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Quelques aspects de l'ensemble XYZBLC de logiciels d'aérotriangulation sont décrits. Le bloc Bute de l'Ordnance Survey, composé de photographies à l'échelle du 1: 24000, a été calculé par modèles indépendants avec les logiciels XYZBLC. On a considéré trois des bandes du bloc comme formant un bloc d'essai et on les a calculées avec diverses combinaisons de canevas de points d'appui. On en tire des conclusions quant à l'utilité des doublets de points d'appui altimétriques et de diverses autres configurations denses de canevas d'appui. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Beschreibung einiger Aspekte des XYZBLC-Programmsystems zur Aero-triangulation. Ein Block des Ordnance Survey im Bildmassstab 1: 24000 wurde damit nach der Methode der unabhängigen Modelle berechnet. Drei der Streifen des Blocks wurden als Testblock behandelt und mit verschiedenen Passpunktanordnungen berechnet. Es werden Schlussfolgerungen in bezug auf die Nützlichkeit von Zwillingspunkten zur Höhenorientierung und andere dichte Passpunktanordnungen gezogen.

Notizen: The wide availability of reconnaissance frame photography, together with the advantage of high image resolution that such photography provides and the extreme flight conditions under which it can be taken, means that it is of great interest to photogrammetrists. However, the geometry of the image is invariably distorted due to the mode of operation of the camera. In this paper, the effects of the focal plane shutter and apparent image motion compensation on the geometry of the photographs are considered.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLe fait que la photographic de reconnaissance soil très répandue, conjointe-ment aux avantages que présente la grande résolution des images fournies par ces systèmes et les conditions extrêmes de vol dans lesquelles on peut les prendre, milite pour une prise en compte de lew intérêt par les photogrammètres. Toutefois la géométrie de ces images est systématiquement déformée par suite du mode de fonctionnement de la chambre. On traite dans cet article des effets de l'obturateur focal et de la compensation du filé de l'image sur la géométrie des photographies.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie grosse Verbreitung von Erkundungsfotos zusammen mit der grossen Auflösung solcher Fotos und den extremen Bedingungen unter denen sie auf-genommen wurden, lassen diese auch für den Photogrammeter interessant erscheinen. Die Geometrie dieser Bilder ist jedoch infolge der speziellen Kamera-funktion verzerrt. Im Artikel werden die Einflüsse des Schlitzverschlusses und des Bildwanderungsausgleichs auf die Bildgeometrie untersucht.

Notizen: Book Reviewed in this article:AERIAL PHOTOGRAPHY. By G. S. Kumar.MANUAL OF PHOTOGRAMMETRY (Fourth Edition). Editor-in-Chief: C. C. Slama.

Notizen: Two complementary measuring instruments are described which use a very simple principle and which take three dimensional measurements or plots directly from small objects. The first instrument can achieve accuracies of ± 0·3 mm on objects whose largest dimension is 300 mm. The second can achieve ± 0·02 mm on objects smaller than a 25 mm cube.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn présente deux instruments de mesure complémentaires el de principe très simple permettant de relever dans l'espace des coordonnées sur de petits objets, le premier avec une exactitude de ± 0.3 mm sur des objets de dimension inférieure à 300 mm, le second avec une exactitude de ± 0.02 mm sur des objets de dimension inférieure à 25 mm.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungBeschreibung von zwei Zusatzmessgeräten, die auf einem sehr einfachen Prinzip beruhen und mit denen dreidimensionale Messungen oder Auswertungen von kleinen Objekten direkt durchgeführt werden konnen. Mil dem ersten Gerät kann eine Genauigkeit von ± 0,3 mm bei maximalen Objekt abmessungen von 300 mm und mit dem zweiten von ± 0,02 mm bein Objekten, die kleiner als ein 25 mm-Kubus sind, erreicht werden.